Editing Vietnamese language

{{pp|small=yes}}
{{Short description|Austroasiatic language}}
{{Infobox language
| name             = Vietnamese
| nativename       = {{lang|vi|Tiếng Việt}}
| pronunciation    = {{IPA|vi|tiəŋ˧˦ viət̚˧˨ʔ|}} (Hà Nội)<br />{{IPA|vi|tiəŋ˦˧˥ viək̚˨˩ʔ|}} (Huế)<br />{{IPA|vi|tiəŋ˦˥ viək̚˨˩˨|}} ~ {{IPA|vi|tiəŋ˦˥ jiək̚˨˩˨|}} (Sài Gòn)
| states           = [[Vietnam]], [[China]] <small>([[Dongxing, Guangxi]])</small>
| speakers         = [[first language|L1]]: {{sigfig|86.130550|2}} million (2019–2023)<ref name="e28|vie|Vietnamese">{{e28|vie|Vietnamese}}</ref>
| ethnicity        = 
| speakers2        = [[second language|L2]]: {{sigfig|10.853000|2}} million (2024)<ref name="e28|vie|Vietnamese">{{e28|vie|Vietnamese}}</ref><br/>Total: {{sigfig|96.983550|2}} million (2019–2024)<ref name="e28|vie|Vietnamese">{{e28|vie|Vietnamese}}</ref>
| speakers_label   = Speakers
| date             = 
| ref              = 
| familycolor      = Austroasiatic
| fam2             = [[Vietic languages|Vietic]]
| fam3             = [[Vietic languages|Viet]]–[[Mường language|Mường]]
| ancestor         = [[#History|Old Vietnamese]]
| ancestor2        = [[Middle Vietnamese]]
| script           = [[Latin script|Latin]] ([[Vietnamese alphabet]])<br />[[Vietnamese Braille]]<br />[[Chữ Nôm]] (historical)
| nation           = [[Vietnam]]
| minority         = [[Czech Republic]]<ref>{{cite web | url=https://www.idnes.cz/zpravy/domaci/vietnamci-oficialni-narodnostni-mensinou.A130703_133019_domaci_jj# | title=Česko má nové oficiální národnostní menšiny. Vietnamce a Bělorusy | date=3 July 2013 }}</ref><br />[[Slovakia]]<ref>{{cite web | url=https://ec.europa.eu/migrant-integration/news/slovakia-vietnamese-community-granted-national-minority-status_en | title=Slovakia: Vietnamese community granted national minority status &#124; European Website on Integration | date=7 June 2023 }}</ref>
| agency           = [[Vietnam Academy of Social Sciences]]
| iso1             = vi
| iso2             = vie
| iso3             = vie
| lingua           = 46-EBA<!-- https://web.archive.org/web/20060102201830/http://www.linguasphere.org/major.pdf -->
| map              = Natively Vietnamese-speaking areas.png
| mapcaption       = Areas within Vietnam with majority Vietnamese speakers, mirroring the [[List of ethnic groups in Vietnam|ethnic landscape]] of Vietnam with [[ethnic Vietnamese]] dominating around the lowland pale of the country.<ref>From ''Ethnologue'' (2009, 2013)</ref>
| notice           = IPA
| glotto           = viet1252
| glottorefname    = Vietnamese Language
}}
{{Contains special characters|Vietnamese}}

'''Vietnamese''' ({{lang|vi|Tiếng Việt}}) is an [[Austroasiatic languages|Austroasiatic language]] [[Speech|spoken]] primarily in [[Vietnam]] where it is the [[official language]]. It belongs to the [[Vietic languages|Vietic subgroup]] of the Austroasiatic [[language family]].<ref>{{Cite book |last=Taylor |first=K. W. |url=https://books.google.com/books?id=P2HP31kOSA4C&dq=Vietic+peoples&pg=PA51 |title=A History of the Vietnamese |date=2013-05-09 |publisher=Cambridge University Press |isbn=978-0-521-87586-8 |pages=51 |language=en}}</ref> Vietnamese is spoken natively by around 86 million people,<ref name="e28|vie|Vietnamese"/> and as a second language by 11 million people,<ref name="e28|vie|Vietnamese"/> several times as many as the rest of the Austroasiatic family combined.<ref>{{cite book|last=Driem|first=George van|author-link=George van Driem|title=Languages of the Himalayas, Volume One|url=https://books.google.com/books?id=fiavPYCz4dYC&pg=PA264|year=2001|publisher=BRILL|isbn=90-04-12062-9|page=264|quote= Of the approximately 90 millions speakers of Austroasiatic languages, over 70 million speak Vietnamese, nearly ten million speak Khmer and roughly five million speak Santali.}}</ref> It is the [[native language]] of [[Vietnamese people|ethnic Vietnamese]] (Kinh), as well as the [[second language|second]] or [[First language|first]] language for [[List of ethnic groups in Vietnam|other ethnicities of Vietnam]], and used by [[Overseas Vietnamese|Vietnamese diaspora]] in the world.

Like many languages in [[Southeast Asia]] and [[East Asia]], Vietnamese is highly [[analytic language|analytic]] and is [[tone (linguistics)|tonal]]. It has [[head-initial]] directionality, with [[subject–verb–object]] order and modifiers following the words they modify. It also uses noun [[classifier (linguistics)|classifier]]s. Its vocabulary has had significant influence from [[Middle Chinese]] and [[French language|French]].<ref>{{Cite journal | url=https://hal.science/hal-02868709/document | title=The integration of French loanwords into Vietnamese: A corpus-based analysis of tonal, syllabic and segmental aspects | first1=Vera | last1=Scholvin | first2=Judith | last2=Meinschaefer | journal=Journal of the Southeast Asian Linguistics Society | year=2018}}</ref> Although most of its phonological words are monosyllabic, Vietnamese has systems of compounding and reduplication which leads to the majority of Vietnamese vocabulary being disyllabic and trisyllabic words.<ref>{{Cite journal|url=http://www.tandfonline.com/doi/full/10.1080/00437956.1963.11659787|title=The Problem of the Word in Vietnamese|first=Laurence C.|last=Thompson|date=January 17, 1963|journal=WORD|volume=19|issue=1|pages=39–52|via=CrossRef|doi=10.1080/00437956.1963.11659787}}</ref>

Vietnamese is written using the [[Vietnamese alphabet]] ({{lang|vi|chữ Quốc ngữ}}). The alphabet is based on the [[Latin script]] and was officially adopted in the early 20th century during [[French Indochina|French rule of Vietnam]]. It uses [[Digraph (orthography)|digraphs]] and [[diacritic]]s to mark [[Tone (linguistics)|tone]]s and some [[phoneme]]s. Vietnamese was historically written using {{lang|vi|[[chữ Nôm]]}}, a [[logographic]] script using [[Chinese characters]] ({{lang|vi|[[chữ Hán]]}}) to represent [[Sino-Vietnamese vocabulary]] and some native Vietnamese words, together with many locally invented characters representing other words.<ref>{{Cite web|url=https://www.britannica.com/art/Vietnamese-literature|title=Vietnamese literature|website=Encyclopedia Britannica|language=en|access-date=2019-04-13}}</ref><ref>{{cite book |last=Li |first=Yu |title=The Chinese Writing System in Asia: An Interdisciplinary Perspective |publisher=Routledge |year=2020 |isbn=978-1-00-069906-7 |pages=102–103}}</ref>

==Classification==
[[File:Pagan races of the Malay Peninsula (1906) (14781207342).jpg|thumb|right|A 1906 analysis map of [[Austroasiatic languages]] (previously known as Mon-Annam languages) by British linguists [[Walter William Skeat]] and [[Charles Otto Blagden]]. Vietnamese is shown as Annamese.]]
Early [[Comparative method|linguistic work]] in the late 19th and early 20th centuries ([[James Richardson Logan|Logan]] 1852, [[Charles James Forbes Smith-Forbes|Forbes]] 1881, [[Friedrich Müller (linguist)|Müller]] 1888, [[Ernst Kuhn|Kuhn]] 1889, [[Wilhelm Schmidt (linguist)|Schmidt]] 1905, [[Jean Przyluski|Przyluski]] 1924, and [[Paul K. Benedict|Benedict]] 1942)<ref>{{cite web
  | title = Mon–Khmer languages: The Vietic branch
  | publisher = SEAlang Projects
  | url = http://sealang.net/mk/vietic-intro.htm
  | access-date =November 8, 2006
}}</ref> classified Vietnamese as belonging to the [[Mon–Khmer languages|Mon–Khmer]] branch of the [[Austroasiatic languages|Austroasiatic language family]] (which also includes the [[Khmer language|Khmer]] language spoken in [[Cambodia]], as well as various smaller and/or [[regional language]]s, such as the [[Munda languages|Munda]] and [[Khasi language|Khasi]] languages spoken in eastern India, and others in [[Laos]], southern China and parts of Thailand). In 1850, British lawyer [[James Richardson Logan]] detected striking similarities between the [[Korku language]] in [[Central India]] and Vietnamese. He suggested that [[Korku language|Korku]], [[Mon language|Mon]], and Vietnamese were part of what he termed "Mon–Annam languages" in a paper published in 1856. Later, in 1920, French-Polish linguist [[Jean Przyluski]] found that [[Muong language|Mường]] is more closely related to Vietnamese than other Mon–Khmer languages, and a Viet–Muong subgrouping was established, also including [[Thavung language|Thavung]], [[Chut language|Chut]], [[Cuoi language|Cuoi]], etc.<ref>Ferlus, Michel. 1996. Langues et peuples viet-muong. ''[[Mon-Khmer Studies]]'' 26. 7–28.</ref> The term "Vietic" was proposed by Hayes (1992),<ref name = "Hayes">{{cite journal | last1 = Hayes | first1 = La Vaughn H | year = 1992 | title = Vietic and Việt-Mường: a new subgrouping in Mon-Khmer | journal = [[Mon-Khmer Studies]] | volume = 21 | pages = 211–228 }}</ref> who proposed to redefine Viet–Muong as referring to a subbranch of Vietic containing only Vietnamese and [[Muong language|Mường]]. The term "[[Vietic languages|Vietic]]" is used, among others, by [[Gérard Diffloth]], with a slightly different proposal on subclassification, within which the term "Viet–Muong" refers to a lower subgrouping (within an eastern Vietic branch) consisting of Vietnamese dialects, Mường dialects, and [[Nguồn language|Nguồn]] (of [[Quảng Bình Province]]).<ref>Diffloth, Gérard. (1992). "Vietnamese as a Mon-Khmer language". ''Papers from the First Annual Meeting of the Southeast Asian Linguistics Society'', 125–128. Tempe, Arizona: Program for Southeast Asian Studies.</ref>

==History==
Austroasiatic is believed to have dispersed around 2000 BC.{{sfn|Alves|2020|p=xviii}}
The arrival of the agricultural [[Phùng Nguyên culture]] in the [[Red River Delta]] at that time may correspond to the Vietic branch.{{sfn|Sidwell|Alves|2021|p=189}}

This ancestral Vietic was typologically very different from later Vietnamese.
As well as monosyllabic roots, it had [[sesquisyllabic]] roots consisting of a reduced syllable followed by a full syllable, and featured many consonant clusters.
Both of these features are found elsewhere in Austroasiatic and in modern conservative Vietic languages south of the Red River area.{{sfn|Alves|2021|p=661}}
The language was non-tonal, but featured glottal stop and voiceless fricative codas.{{sfn|Alves|2021|p=662}}

Borrowed vocabulary indicates early contact with speakers of [[Tai languages]] in the last millennium BC, which is consistent with genetic evidence from [[Dong Son culture]] sites.{{sfn|Sidwell|Alves|2021|p=189}}
Extensive contact with [[Chinese language|Chinese]] began from the [[Han dynasty]] (2nd century BC).{{sfn|Alves|2020|p=xix}}
At this time, Vietic groups began to expand south from the Red River Delta and into the adjacent uplands, possibly to escape Chinese encroachment.{{sfn|Sidwell|Alves|2021|p=189}}
The oldest layer of loans from Chinese into northern Vietic (which would become the Viet–Muong subbranch) date from this period.{{sfn|Alves|2021|p=663}}

The northern Vietic varieties thus became part of the [[Mainland Southeast Asia linguistic area]], in which languages from genetically unrelated families converged toward characteristics such as [[Isolating language|isolating morphology]] and similar syllable structure.{{sfn|Alves|2021|p=659}} Many languages in this area, including Viet–Muong, underwent a process of [[tonogenesis]], in which distinctions formerly expressed by final consonants became phonemic [[tone (linguistics)|tonal distinctions]] when those consonants disappeared. These characteristics have become part of many of the genetically unrelated languages of Southeast Asia; for example, [[Tsat language|Tsat]] (a member of the [[Malayo-Polynesian languages|Malayo-Polynesian]] group within [[Austronesian languages|Austronesian]]), and Vietnamese each developed tones as a phonemic feature.

[[File:An Nam dịch ngữ.jpg|thumb|An Nam quốc dịch ngữ 安南國譯語 records the pronunciations of 15th-century Vietnamese, such as for 天 (sky) - 雷 /luei/ representing blời (Modern Vietnamese: trời).<ref name=":5" />]]
After the split from Muong around the end of the first millennium AD, the following stages of Vietnamese are commonly identified:{{sfn|Alves|2020|p=xviii}}
;Ancient (or Old) Vietnamese
:(to {{circa|lk=no|1500}}) Sources include the Ming glossary {{tlit|zh|Ānnánguó yìyǔ}} ({{lang|zh|安南國譯語}}, c. 15th century) from the ''[[Huayi yiyu]]'' series,{{efn|The Bureau of Interpreters used Chinese approximations to record Vietnamese rather than use Sino-Vietnamese to record as has been done in Annan Yiyu 安南譯語, a prior work.<ref name=":5">{{Cite book |last=Vương |first=Lộc |title=An Nam dịch ngữ |date=1995 |publisher=NXB Đà Nẵng |location=Vietnam |language=vi}}</ref>}} and a Buddhist sutra recorded in an early form of chu Nom, variously dated to the 12th and 15th centuries.{{sfn|Nguyễn|2009|p=678}}{{sfn|Shimizu|2015|p=136}} Compared with Proto-Vietic, the language had lost the voicing distinction on stop initials, giving rise to a [[tone split]], and [[implosive consonant|implosive]] initials had become [[nasal consonant|nasal]]s.{{sfn|Shimizu|2015|pp=151–152}} Most of the minor syllables of Proto-Vietic were still present.{{sfn|Shimizu|2015|pp=141–142}}
;Middle Vietnamese
:(16th to 19th centuries) The language found in ''[[Dictionarium Annamiticum Lusitanum et Latinum]]'' (1651) of the Jesuit missionary [[Alexandre de Rhodes]].{{sfn|Nguyễn|2009|p=678}} Another famous dictionary of this period was written by [[Pierre Pigneau de Behaine]] in 1773 and published by [[Jean-Louis Taberd]] in 1838.
;Modern Vietnamese
:(from the 19th century){{sfn|Nguyễn|2009|p=678}}

After expelling the Chinese at the beginning of the 10th century, the [[Ngô dynasty]] adopted [[Classical Chinese]] as the formal medium of government, scholarship and literature. With the dominance of Chinese came wholesale importation of Chinese vocabulary. The resulting [[Sino-Vietnamese vocabulary]] makes up about a third of the Vietnamese lexicon in all realms, and may account for as much as 60% of the vocabulary used in formal texts.{{sfn|DeFrancis|1977|p=8}}

Vietic languages were confined to the northern third of modern Vietnam until the "southward advance" ([[Nam tiến]]) from the late 15th century.{{sfn|Sidwell|Alves|2021|p=187}}
The conquest of the ancient nation of [[Champa]] and the conquest of the [[Mekong Delta]] led to an expansion of the Vietnamese people and language, with distinctive local variations emerging.

After France invaded Vietnam in the late 19th century, French gradually replaced Literary Chinese as the official language in education and government. Vietnamese adopted many French terms, such as {{lang|vi|đầm}} ('dame', from {{lang|fr|madame}}), {{lang|vi|ga}} ('train station', from {{lang|fr|gare}}), {{lang|vi|sơ mi}} ('shirt', from {{lang|fr|chemise}}), and {{lang|vi|búp bê}} ('doll', from {{lang|fr|poupée}}), resulting in a language that was Austroasiatic but with major Sino-influences and some minor French influences from the French colonial era.

===Proto-Vietic{{anchor|Proto-Vietnamese}}===
The following diagram shows the consonants of Proto-Vietic, along with the outcomes in the modern language:{{sfn|Ferlus|1992|p=111}}{{sfn|Ferlus|2009|p=96}}<ref name="ferlus1982">
{{citation
|last=Ferlus
|first=Michel
|title=Spirantisation des obstruantes médiales et formation du système consonantique du vietnamien 
|url=https://halshs.archives-ouvertes.fr/halshs-01063845
|year=1982
|journal=Cahiers de Linguistique Asie Orientale
|volume=11
|issue=1
|pages=83–106
|doi=10.3406/clao.1982.1105}}.
</ref>{{efn|The branch Ferlus called Viet–Muong is today called Vietic, with the former term now restricted to the subbranch contsisting of Vietnames and Muong.{{sfn|Ferlus|2009|p=95}}}}

:{| class="wikitable"
|+ Proto-Vietic consonants
|-
! colspan="2" |
! [[labial consonant|Labial]]
! [[Alveolar consonant|Alveolar]]
! [[Palatal consonant|Palatal]]
! [[Velar consonant|Velar]]
! [[glottal consonant|Glottal]]
|-
! colspan="2" |[[Nasal stop|Nasal]]
|*{{IPA|m}} > ''m''
|*{{IPA|n}} > ''n''
|*{{IPA|ɲ}} > ''nh''
|*{{IPA|ŋ}} > ''ng/ngh''
|
|-
! rowspan="4" | [[Stop consonant|Stop]]
! <small>tenuis</small>
| *{{IPA|p}} > ''b''
| *{{IPA|t}} > ''đ''
| *{{IPA|c}} > ''ch''
| *{{IPA|k}} > ''k/c/q''
| *{{IPA|ʔ}} > ''#''
|-
! <small>voiced</small>
| *{{IPA|b}} > ''b''
| *{{IPA|d}} > ''đ''
| *{{IPA|ɟ}} > ''ch''
| *{{IPA|ɡ}} > ''k/c/q''
|
|-
! <small>aspirated</small>
| *{{IPA|pʰ}} > ''ph''
| *{{IPA|tʰ}} > ''th''
|
| *{{IPA|kʰ}} > ''kh''
|
|-
! <small>implosive</small>
| *{{IPA|ɓ}} > ''m''
| *{{IPA|ɗ}} > ''n''
| *{{IPA|ʄ}} > ''nh''
|
|
|-
! colspan="2" | [[Affricate consonant|Affricate]]
|
|
| *{{IPA|tʃ}} > ''x''
|
|
|-
! colspan="2" | [[Fricative]]
|
| *{{IPA|s}} > ''t''
|
|
| *{{IPA|h}} > ''h''
|-
! colspan="2" | [[Approximant]]
| *{{IPA|w}} > ''v''
| *{{IPA|l}} > ''l''
| *{{IPA|j}} > ''d''
|
|
|-
! colspan="2" | [[Rhotic consonant|Rhotic]]
|
| *{{IPA|r}} > ''r''
|
|
|
|}

The aspirated stops are infrequent and result from clusters of stops and *{{IPA|/h/}}.{{sfn|Ferlus|2009|p=96}}
The proto-phoneme *{{IPA|/tʃ/}} is also infrequent, and has reflexes only in Viet-Muong. However, it occurs in some important words and is cognate with [[Khmu language|Khmu]] {{IPA|/c/}}.{{sfn|Ferlus|2009|p=96}}
Ferlus 1992 also had additional [[phoneme]]s *{{IPA|/dʒ/}} and *{{IPA|/ɕ/}}.{{sfn|Ferlus|1992|p=112}}

Proto-Vietic had monosyllables CV(C) and sesquisyllables C-CV(C).{{sfn|Ferlus|2009|p=96}}
The following initial clusters occurred, with outcomes indicated:
* *pr, *br, *tr, *dr, *kr, *gr > {{IPA|/kʰr/}} > {{IPA|/kʂ/}} > ''s''
* *pl, *bl > MV ''bl'' > Northern ''gi'', Southern ''tr''
* *kl, *gl > MV ''tl'' > ''tr''
* *ml > MV ''ml'' > ''mnh'' > ''nh''
* *kj > ''gi''

=== Lenition of medial consonants ===
As noted above, Proto-Vietic had [[sesquisyllabic]] words with an initial [[minor syllable]] (in addition to, and independent of, initial clusters in the main syllable). When a minor syllable occurred, the main syllable's initial consonant was [[intervocalic]] and as a result suffered [[lenition]], becoming a voiced fricative.{{sfn|Ferlus|1992|p=113}} These fricatives were not present in Proto-Viet–Muong, as indicated by their absence in [[Muong language|Mường]], but were present in Vietnamese until the 15th or 16th centuries.{{sfn|Ferlus|1992|p=119}} Subsequent loss of the minor-syllable prefixes phonemicized the fricatives. Ferlus 1992 proposes that originally there were both voiced and voiceless fricatives, corresponding to original voiced or voiceless stops,{{sfn|Ferlus|1992}} but Ferlus 2009 appears to have abandoned that hypothesis, suggesting that stops were softened and voiced at approximately the same time, according to the following pattern:{{sfn|Ferlus|2009|p=96}}
*{{IPA|*p, *b}} > {{IPA|/β/}} > ''v''. In [[Middle Vietnamese]], the outcome of these sounds was written with a hooked ''b'' (ꞗ), representing a {{IPA|/β/}} that was still distinct from ''v'' (then pronounced {{IPA|/w/}}).
*{{IPA|*t, *d}} > {{IPA|/ð/}} > ''d''
*{{IPA|*c, *ɟ, *tʃ}} > {{IPA|/ʝ/}} > ''gi''
*{{IPA|*k, *ɡ}} > {{IPA|/ɣ/}} > ''g/gh''
*{{IPA|*s}} > {{IPA|/r̝/}} > ''r''

===Origin of tones===
Proto-Vietic did not have tones. Tones developed later in some of the daughter languages from distinctions in the initial and final consonants. Vietnamese tones developed as follows:<ref name="Haudricourt 2017 122–128">{{Cite journal|last=Haudricourt|first=André-Georges|date=2017|title=La place du Vietnamien dans les langues Austroasiatiques|trans-title=The place of Vietnamese in Austroasiatic (1953)|url=https://halshs.archives-ouvertes.fr/halshs-01631477/document|journal=Bulletin de la Société de Linguistique de Paris|volume=49|issue=1|pages=122–128}}</ref>

:{| class="wikitable" style="text-align:center;"
|-
! [[Register (phonology)|Register]]
! Initial consonant
! Smooth ending
! Glottal ending
! Fricative ending
|-
! High (first) register
| Voiceless
| A1 ''ngang'' "level"
| B1 ''sắc'' "sharp"
| C1 ''hỏi'' "asking"
|-
! Low (second) register
| Voiced
| A2 ''huyền'' "deep"
| B2 ''nặng'' "heavy"
| C2 ''ngã'' "tumbling"
|}

Glottal-ending syllables ended with a glottal stop {{IPA|/ʔ/}}, while fricative-ending syllables ended with {{IPA|/s/}} or {{IPA|/h/}}. Both types of syllables could co-occur with a resonant (e.g. {{IPA|/m/}} or {{IPA|/n/}}).

At some point, a [[tone split]] occurred, as in many other [[Mainland Southeast Asia linguistic area|mainland Southeast Asian languages]]. Essentially, an [[allophonic]] distinction developed in the tones, whereby the tones in syllables with voiced initials were pronounced differently from those with voiceless initials. (Approximately speaking, the voiced [[allotone]]s were pronounced with additional [[breathy voice]] or [[creaky voice]] and with lowered pitch. The quality difference predominates in today's northern varieties, e.g. in [[Hanoi]], while in the southern varieties the pitch difference predominates, as in [[Ho Chi Minh City]].) Subsequent to this, the plain-voiced stops became voiceless and the allotones became new phonemic tones.

The implosive stops ({{IPA|ɓ}}, {{IPA|ɗ}} and {{IPA|ʄ}}) were unaffected, and in fact developed tonally as if they were unvoiced.{{citation needed|date=December 2024}} (This behavior is common to all East Asian languages with implosive stops.)
These stops merged with the corresponding nasals ({{IPA|m}}, {{IPA|n}} and {{IPA|ɲ}}) before the Old Vietnamese period.{{sfn|Ferlus|1992|p=117}}{{sfn|Shimizu|2015|p=152}}

As noted above, consonants following minor syllables became voiced fricatives. The minor syllables were eventually lost, but not until the tone split had occurred. As a result, words in modern Vietnamese with voiced fricatives occur in all six tones, and the tonal register reflects the voicing of the minor-syllable prefix and not the voicing of the main-syllable stop in Proto-Vietic that produced the fricative. For similar reasons, words beginning with {{IPA|/l/}} and {{IPA|/ŋ/}} occur in both registers. (Thompson 1976 reconstructed voiceless resonants to account for outcomes where resonants occur with a first-register tone,<ref>{{cite journal
|last=Thompson
|first=Laurence C.
|title=Proto-Viet–Muong Phonology
|journal=Oceanic Linguistics Special Publications
|volume=13
|series=Austroasiatic Studies Part II
|year=1976
|pages=1113–1203
|publisher=University of Hawai'i Press
|jstor=20019198
}}</ref> but this is no longer considered necessary, at least by Ferlus.)

A large number of words were borrowed from [[Middle Chinese]], forming part of the [[Sino-Vietnamese vocabulary]]. These caused the original introduction of the retroflex sounds {{IPA|/ʂ/}} and {{IPA|/ʈ/}} (modern ''s'', ''tr'') into the language.

===Old Vietnamese===
Old (or Ancient) Vietnamese separated from Muong around the 9th century. The sources for the reconstruction of Old Vietnamese are [[Chu Nom|Nom]] texts, such as the 12th-century/1486 Buddhist scripture ''Phật thuyết Đại báo phụ mẫu ân trọng kinh'' ("Sūtra explained by the Buddha on the Great Repayment of the Heavy Debt to Parents"),{{sfn|Gong|2019|p=60}} old inscriptions, and a late 13th-century (possibly 1293) ''[https://ctext.org/wiki.pl?if=gb&chapter=224481&remap=gb Annan Jishi]'' glossary by Chinese diplomat [[:zh:陈孚|Chen Fu]] (c. 1259 – 1309).{{sfn|Nguyen|2018|p=162}}

:{| class="wikitable" style=text-align:center
|+ Old Vietnamese consonants{{sfn|Shimizu|2015|pp=143–155}}{{sfn|Gong|2019|pp=60–61}}
|-
! colspan="2" |
! [[labial consonant|Labial]]
! [[Alveolar consonant|Alveolar]]
! [[Palatal consonant|Palatal]]
! [[Velar consonant|Velar]]
! [[glottal consonant|Glottal]]
|-
! colspan="2" |[[Nasal stop|Nasal]]
| {{IPA|m}} > ''m''
| {{IPA|n}} > ''n''
| {{IPA|ɲ}} > ''nh''
| {{IPA|ŋ}} > ''ng/ngh''
|
|-
! rowspan="2" | [[Stop consonant|Stop]]
! <small>tenuis</small>
| {{IPA|p}} > ''b''
| {{IPA|t}} > ''đ''
| {{IPA|c}} > ''ch''
| {{IPA|k}} > ''k/c/q''
| {{IPA|ʔ}} > ''#''
|-
! <small>aspirated</small>
| {{IPA|pʰ}} > ''ph''
| {{IPA|tʰ}} > ''th''
|
| {{IPA|kʰ}} > ''kh''
|
|-
! colspan="2" | [[Affricate consonant|Affricate]]
|
|
| {{IPA|tʃ}} > ''x''
|
|
|-
! rowspan="2" | [[Fricative]]
! <small>voiced</small>
| {{IPA|β}} > ''v''
| {{IPA|ð}} > ''d''
| {{IPA|ʝ}} > ''gi''
| {{IPA|ɣ}} > ''g/gh''
|
|-
! <small>voiceless</small>
|
| {{IPA|s}} > ''t''
|
|
| {{IPA|h}} > ''h''
|-
! colspan="2" | [[Approximant]]
| {{IPA|w}} > ''v''
| {{IPA|l}} > ''l''
| {{IPA|j}} > ''d''
|
|
|-
! colspan="2" | [[Rhotic consonant|Rhotic]]
|
| {{IPA|r}} > ''r''
|
|
|
|}

The {{lang|vi|Đại báo}} used Chinese characters phonetically where each word, monosyllabic in Modern Vietnamese, is written with two Chinese characters or in a composite character made of two different characters.{{sfn|Gong|2019|pp=58–59}} This conveys the transformation of the Vietnamese lexicon from sesquisyllabic to fully [[monosyllabic language|monosyllabic]] under the pressure of Chinese linguistic influence, characterized by linguistic phenomena such as the reduction of minor syllables; loss of affixal morphology drifting towards analytical grammar; simplification of major syllable segments, and the change of suprasegment instruments.{{sfn|Gong|2019|p=58}} For example, the modern Vietnamese word {{lang|vi|trời}} 'heaven' was ''*plời'' in Old Vietnamese and ''blời'' in Middle Vietnamese.{{sfn|Gong|2019|pp=55, 59}}

Subsequent changes to initial consonants included:{{sfn|Ferlus|1992|p=119}}
* re-introduction of implosive stops {{IPA|p}} > {{IPA|ɓ}} and {{IPA|t}} > {{IPA|ɗ}}
* {{IPA|s}} > {{IPA|ts}} > {{IPA|t}}
* {{IPA|tʃ}} > {{IPA|ɕ}}
* a merger {{IPA|j}} > {{IPA|ð}}

===Middle Vietnamese===
The writing system used for Vietnamese is based closely on the system developed by [[Alexandre de Rhodes]] for his 1651 ''[[Dictionarium Annamiticum Lusitanum et Latinum]]''. It reflects the pronunciation of the Vietnamese of Hanoi at that time, a stage commonly termed ''Middle Vietnamese'' ({{lang|vi|tiếng Việt trung đại}}). The pronunciation of the "rime" of the syllable, i.e. all parts other than the initial consonant (optional {{IPA|/w/}} glide, vowel nucleus, tone and final consonant), appears nearly identical between Middle Vietnamese and modern Hanoi pronunciation. On the other hand, the Middle Vietnamese pronunciation of the initial consonant differs greatly from all modern dialects, and in fact is significantly closer to the modern Saigon dialect than the modern Hanoi dialect.

[[File:Dictionarium Annamiticum Lusitanum et Latinum (Bayerische Staatsbibliothek).pdf|thumb|right|upright|page=43|The first page of the [[B with flourish|ꞗ]] section in [[Alexandre de Rhodes]]'s {{lang|la|[[Dictionarium Annamiticum Lusitanum et Latinum]]}} (''Vietnamese–Portuguese–Latin dictionary'')]]
The following diagram shows the orthography and pronunciation of Middle Vietnamese:

:{| class="wikitable" style=text-align:center
|+ Middle Vietnamese consonants
|-
! colspan="2" |
! [[labial consonant|Labial]]
! [[Dental consonant|Dental]]/<br />[[Alveolar consonant|Alveolar]]
! [[Retroflex consonant|Retroflex]]
! [[Palatal consonant|Palatal]]
! [[Velar consonant|Velar]]
! [[glottal consonant|Glottal]]
|-
! colspan="2" | [[Nasal consonant|Nasal]]
| ''m'' {{IPAblink|m}}
| ''n'' {{IPAblink|n}}
|
| ''nh'' {{IPAblink|ɲ}}
| ''ng/ngh'' {{IPAblink|ŋ}}
|
|-
! rowspan="3" | [[Stop consonant|Stop]]
! <small>tenuis</small>
| ''p'' {{IPAblink|p}}{{ref|p|1}}
| ''t'' {{IPAblink|t}}
| ''tr'' {{IPAblink|ʈ}}
| ''ch'' {{IPAblink|c}}
| ''c/k'' {{IPAblink|k}}
|
|-
! <small>aspirated</small>
| ''ph'' {{IPAblink|pʰ}}
| ''th'' {{IPAblink|tʰ}}
|
|
| ''kh'' {{IPAblink|kʰ}}
|
|-
! <small>implosive</small>
| ''b'' {{IPAblink|ɓ}}
| ''đ'' {{IPAblink|ɗ}}
|
|
|
|
|-
! rowspan="2" | [[Fricative consonant|Fricative]]
! <small>voiceless</small>
|
|
| ''s'' {{IPAblink|ʂ}}
| ''x'' {{IPAblink|ɕ}}
|
| ''h'' {{IPAblink|h}}
|-
! <small>voiced</small>
| ''ꞗ'' {{IPAblink|β}}{{ref|hookb|2}}
| ''d'' {{IPAblink|ð}}
|
| ''gi'' {{IPAblink|ʝ}}
| ''g/gh'' {{IPAblink|ɣ}}
|
|-
! colspan="2" | [[Approximant consonant|Approximant]]
| ''v/u/o'' {{IPAblink|w}}
| ''l'' {{IPAblink|l}}
|
| ''y/i/ĕ'' {{IPAblink|j}}{{ref|yod|3}}
|
|
|-
! colspan="2" | [[Rhotic consonant|Rhotic]]
|
| colspan="2" | ''r'' {{IPAblink|r}}
|
|
|
|}

{{note|p|1}} {{IPA|[p]}} occurs only at the end of a syllable.<br />
{{note|hookb|2}} This letter, {{angbr|[[ꞗ]]}}, is no longer used.<br />
{{note|yod|3}} {{IPA|[j]}} does not occur at the beginning of a syllable, but can occur at the end of a syllable, where it is notated ''i'' or ''y'' (with the difference between the two often indicating differences in the quality or length of the preceding vowel), and after {{IPA|/ð/}} and {{IPA|/β/}}, where it is notated ''ĕ''. This ''ĕ'', and the {{IPA|/j/}} it notated, have disappeared from the modern language.

Note that ''b'' {{IPA|[ɓ]}} and ''p'' {{IPA|[p]}} never contrast in any position, suggesting that they are allophones.

The language also has three clusters at the beginning of syllables, which have since disappeared:

*''tl'' {{IPA|/tl/}} > modern ''tr'' - tlước > trước (written in chữ Nôm as 𫏾 (⿰車畧) where 車 represented the initial tl- sound).
*''bl'' {{IPA|/ɓl/}} > modern ''gi'' (Northern), ''tr'' (Southern) - blăng > trăng/giăng (written in chữ Nôm as 𪩮 (⿱巴夌) where 巴 represented the initial bl- sound).
*''ml'' {{IPA|/ml/}} > ''mnh'' {{IPA|/mɲ/}} > modern ''nh'' (Northern), l (Southern) - mlời > lời/nhời (written in chữ Nôm as 𠅜 (⿱亠例) where 亠 (simplified from 麻) represented the initial ml- sound).

[[File:Dictionarium Annamiticum Lusitanum et Latinum, breve acute apex.png|thumb|right|de Rhodes's entry for {{lang|vi|dĕó{{apex|u}}}} shows distinct [[breve]]s, [[acute accent|acutes]] and [[Vietnamese tilde|apices]].]]
Most of the unusual correspondences between spelling and modern pronunciation are explained by Middle Vietnamese. Note in particular:
*de Rhodes' system has two different b letters, {{angle bracket|b}} and {{angle bracket|ꞗ}}. The latter apparently represented a [[voiced bilabial fricative]] {{IPA|/β/}}. Within a century or so, both {{IPA|/β/}} and {{IPA|/w/}} had merged as {{IPA|/v/}}, spelled as ''v''.
*de Rhodes' system has a second medial glide {{IPA|/j/}} that is written ''ĕ'' and appears in some words with initial ''d'' and hooked ''b''. These later disappear.
*''đ'' {{IPA|/ɗ/}} was (and still is) [[alveolar consonant|alveolar]], whereas ''d'' {{IPA|/ð/}} was dental. The choice of symbols was based on the dental rather than alveolar nature of {{IPA|/d/}} and its [[allophone]] {{IPA|[ð]}} in Spanish and other Romance languages. The inconsistency with the symbols assigned to {{IPA|/ɓ/}} vs. {{IPA|/β/}} was based on the lack of any such place distinction between the two, with the result that the [[stop consonant]] {{IPA|/ɓ/}} appeared more "normal" than the fricative {{IPA|/β/}}. In both cases, the [[implosive consonant|implosive]] nature of the stops does not appear to have had any role in the choice of symbol.
*''x'' was the [[voiceless alveolo-palatal fricative|alveolo-palatal fricative]] {{IPA|/ɕ/}} rather than the [[voiceless dental sibilant fricative|dental]] {{IPA|/s/}} of the modern language. In 17th-century [[Portuguese language|Portuguese]], the common language of the Jesuits, ''s'' was the [[voiceless alveolar fricative|apico-alveolar sibilant]] {{IPA|/s̺/}} (as still in much of Spain and some parts of Portugal), while ''x'' was a [[Palato-alveolar consonant|palatoalveolar]] {{IPA|/ʃ/}}. The similarity of apicoalveolar {{IPA|/s̺/}} to the Vietnamese [[retroflex consonant|retroflex]] {{IPA|/ʂ/}} led to the assignment of ''s'' and ''x'' as above.

De Rhodes's orthography also made use of an [[Vietnamese tilde|apex]] diacritic on ''{{apex|o}}'' and ''{{apex|u}}'' to indicate a final [[labial-velar nasal]] {{IPA|/ŋ͡m/}}, an allophone of {{IPA|/ŋ/}} that is peculiar to the Hanoi dialect to the present day. An example is {{wt|mkh-mvi|xa{{apex|o}}}} {{IPA|/ɕawŋ͡m<sup>A1</sup>/}}, which later became {{wt|vi|xong}}. This diacritic is often mistaken for a tilde in modern reproductions of early Vietnamese writing.

=== After the Vietnam War ===
{{see also|Vietnamese language in the United States}}
Following the defeat of Southern Vietnam in 1975 by Northern Vietnam in the Vietnam War, the Vietnamese language within Vietnam has gradually shifted towards the Northern dialect.<ref name=":2">{{Cite web |title=The Non Issue of Dialect in Teaching Vietnamese |url=https://people.clas.ufl.edu/apham/files/The-Non-Issue-of-Dialect-in-Teaching-Vietnamese-2008.pdf}}</ref> [[Hanoi]], the largest city in Northern Vietnam was made the capital of Vietnam in 1976. A study stated that "The gap in vocabulary use between speakers in North and South Vietnam is now much narrower than before. There is little to distinguish between how the generations that were born and grew up in the South after 1975 now speak, compared to their peers in the North. This gap is almost non-existent in newspapers, on radio and television, and in websites."<ref name=":2" /> However, this convergence does not apply to emigrants, in which the study states represent "[[culture freeze]]," a phenomenon that describes when culture among emigrants is frozen in time and does not evolve with culture in their home country once they move to a new country. Here, culture freeze describes that the use of the language of emigrants from Vietnam has been "frozen" in both vocabulary and pronunciation, and as languages gradually evolve over time, has become a little different than the present Vietnamese language in Vietnam. Additionally, as immigration to the United States following the Vietnam war was primarily driven due to political reasons, the Southern Vietnamese dialect was initially strongly linked to social identity. During and after the Vietnam War, thousands of Southern Vietnamese immigrated to the United States with the partnership between Saigon and the US.<ref>{{Cite web |title=Resettling Vietnamese Refugees in the United States |url=https://education.nationalgeographic.org/resource/resettling-vietnamese-refugees-united-states/ |access-date=2025-01-15 |website=education.nationalgeographic.org |language=en}}</ref><ref>{{Cite web |last=Batalova |first=Jeanne Batalova Jeanne |date=2023-10-10 |title=Vietnamese Immigrants in the United States |url=https://www.migrationpolicy.org/article/vietnamese-immigrants-united-states |access-date=2025-01-15 |website=migrationpolicy.org |language=en}}</ref> In contrast, during and following the Vietnam War, thousands of Northern Vietnamese moved to the Czech Republic due to Hanoi's partnership with the now obsolete [[Czechoslovak Socialist Republic]]. As a result, today, the Vietnamese language is generally taught through the Northern dialect in the Czech Republic in contrast with the Southern dialect in the United States.{{fix|link=Wikipedia:Citations needed|text=citation needed|class=Template-Fact}}

==Geographic distribution==
[[File:Color-coded Vietnamese language distribution world map counting from 10,000 user or above vector.svg|thumb|Global distribution of speakers]]

As a result of [[overseas Vietnamese|emigration]], Vietnamese speakers are also found in other parts of [[Southeast Asia]], [[East Asia]], [[North America]], [[Europe]], and [[Australia (continent)|Australia]]. Vietnamese has also been officially recognized as a minority language in the [[Czech Republic]].{{efn|1=Citizens belonging to minorities, which traditionally and on long-term basis live within the territory of the Czech Republic, enjoy the right to use their language in communication with authorities and in front of the courts of law (for the list of recognized minorities see [http://www.vlada.cz/en/pracovni-a-poradni-organy-vlady/rnm/historie-a-soucasnost-rady-en-16666/ National Minorities Policy of the Government of the Czech Republic], Belarusian and Vietnamese since 4 July 2013, see [http://zpravy.idnes.cz/vietnamci-oficialni-narodnostni-mensinou-fiq-/domaci.aspx?c=A130703_133019_domaci_jj Česko má nové oficiální národnostní menšiny. Vietnamce a Bělorusy]). The article 25 of the Czech [[Charter of Fundamental Rights and Basic Freedoms]] ensures right of the national and ethnic minorities for education and communication with authorities in their own language. Act No. 500/2004 Coll. (''The Administrative Rule'') in its paragraph 16 (4) (''Procedural Language'') ensures, that a citizen of the Czech Republic, who belongs to a national or an ethnic minority, which traditionally and on long-term basis lives within the territory of the Czech Republic, have right to address an administrative agency and proceed before it in the language of the minority. In the case that the administrative agency does not have an employee with knowledge of the language, the agency is bound to obtain a translator at the agency's own expense. According to Act No. 273/2001 (''About The Rights of Members of Minorities'') paragraph 9 (''The right to use language of a national minority in dealing with authorities and in front of the courts of law'') the same applies for the members of national minorities also in front of the courts of law.}}

As the national language, Vietnamese is the ''[[lingua franca]]'' in Vietnam. It is also spoken by the [[Jing people]] traditionally residing on three islands (now joined to the mainland) off [[Dongxing, Guangxi|Dongxing]] in southern [[Guangxi|Guangxi Province]], [[China]].<ref>{{cite book |title=Language Power and Hierarchy: Multilingual Education in China |given=Linda |surname=Tsung |publisher=Bloomsbury |year=2014 |isbn=978-1-4411-4235-1 |page=188 }}</ref> A large number of Vietnamese speakers also reside in neighboring countries of [[Vietnamese Cambodians|Cambodia]] and [[Vietnamese people in Laos|Laos]].

In the United States, Vietnamese is the [[Vietnamese language in the United States|sixth most spoken language]], with over 1.5 million speakers, who are concentrated in a handful of states. It is the third-most spoken language in Texas and Washington; fourth-most in Georgia, Louisiana, and Virginia; and fifth-most in Arkansas and California.<ref name="Language Map Data Center">{{Citation| url=https://apps.mla.org/map_data| title=MLA Language Map Data Center| publisher=Modern Language Association|access-date=2018-01-20}}</ref> Vietnamese is the third most spoken language in Australia other than English, after Mandarin and Arabic.<ref>{{cite web | url=https://www.abs.gov.au/census/find-census-data/quickstats/2021/AUS | title=2021 Australia, Census All persons QuickStats &#124; Australian Bureau of Statistics }}</ref> In France, it is the most spoken Asian language and the eighth most spoken immigrant language at home.<ref>[http://www.ined.fr/fichier/t_publication/65/publi_pdf1_pop_et_soc_francais_376.pdf La dynamique des langues en France au fil du XXe siècle] Insee, enquête Famille 1999. (in French)</ref>

===Official status===
Vietnamese is the sole official and national language of Vietnam. It is the first language of the majority of the Vietnamese population, as well as a first or second language for the country's [[ethnic groups in Vietnam|ethnic minority groups]].<ref name="Vietnamese language">{{cite encyclopedia
|encyclopedia= Britannica
|title= Vietnamese language
|date= 29 November 2023
|url=https://www.britannica.com/topic/Vietnamese-language
}}</ref>

In the [[Czech Republic]], Vietnamese has been recognized as one of 14 minority languages, on the basis of communities that have resided in the country either traditionally or on a long-term basis. This status grants the [[Vietnamese people in the Czech Republic|Vietnamese community in the country]] a representative on the Government Council for Nationalities, an advisory body of the Czech Government for matters of policy towards national minorities and their members. It also grants the community the right to use Vietnamese with public authorities and in courts anywhere in the country.<ref>{{Cite web|url=https://www.vlada.cz/en/pracovni-a-poradni-organy-vlady/rnm/historie-a-soucasnost-rady-en-16666/|title=National Minorities &#124; Government of the Czech Republic|website=www.vlada.cz}}</ref><ref>[http://zpravy.idnes.cz/vietnamci-oficialni-narodnostni-mensinou-fiq-/domaci.aspx?c=A130703_133019_domaci_jj Česko má nové oficiální národnostní menšiny. Vietnamce a Bělorusy] (in Czech)</ref>

In the U.S. city of [[San Francisco]], municipal services began to be offered in Vietnamese starting in 2024.<ref>{{cite web | url= https://www.nbcnews.com/news/asian-america/san-francisco-vietnamese-official-language-rcna158080# | title=Vietnamese becomes one of San Francisco's official languages | website=[[NBC News]] | date=21 June 2024 }}</ref>

===As a foreign language===
Vietnamese is taught in schools and institutions outside of Vietnam, a large part contributed by its [[Overseas Vietnamese|diaspora]]. In countries with Vietnamese-speaking communities Vietnamese language education largely serves as a role to link descendants of Vietnamese immigrants to their ancestral culture. In neighboring countries and vicinities near Vietnam such as Southern China, Cambodia, Laos, and Thailand, Vietnamese as a foreign language is largely due to trade, as well as recovery and growth of the Vietnamese economy.<ref>[http://thailand.prd.go.th/view_news.php?id=7197&a=3 More Thai Students Interested in Learning ASEAN Languages] {{Webarchive|url=https://web.archive.org/web/20150110064409/http://thailand.prd.go.th/view_news.php?id=7197&a=3 |date=2015-01-10 }}. April 16, 2014. The Government Public Relations Department. Retrieved 2015-01-10.</ref><ref>{{Cite web|url=https://vietnamtimes.org.vn/more-and-more-foreigners-have-need-to-learn-vietnamese-20847.html|title=More and more foreigners have need to learn Vietnamese|first=Vietnam|last=Times|date=May 30, 2020|website=Vietnam Times}}</ref>

Since the 1980s, Vietnamese language schools ({{lang|vi|trường Việt ngữ/ trường ngôn ngữ Tiếng Việt}}) have been established for youth in many Vietnamese-speaking communities around the world such as [[Vietnamese Americans|in the United States]], [[Vietnamese people in Germany|Germany]] and [[Vietnamese people in France|France]].<ref>{{cite web|title=Vietnamese in the United States|editor1-first=Angie|editor1-last=Nguyen|editor2-first=Lien|editor2-last=Dao|publisher=[[California State Library]]|date=May 18, 2007|page=82|access-date=January 10, 2015|url=http://www.library.ca.gov/services/docs/vietnamese.pdf|archive-url=https://web.archive.org/web/20160304200121/http://www.library.ca.gov/services/docs/vietnamese.pdf|archive-date=March 4, 2016|url-status=dead|df=mdy-all}}</ref><ref>{{cite encyclopedia|title=Vietnamese Immigration|first=Ha|last=Lam|encyclopedia=Encyclopedia of Bilingual Education|editor-first=Josué M.|editor-last=González|location=Thousand Oaks, California|publisher=[[SAGE Publications]]|year=2008|pages=884–887|isbn=978-1-4129-3720-7|url=https://books.google.com/books?id=c_5yAwAAQBAJ&pg=PT933}}</ref><ref name="vietteachlearnoverwhelminggermany">[http://www.vietnambreakingnews.com/2013/09/vietnamese-teaching-and-learning-overwhelming-germany/ Vietnamese teaching and learning overwhelming Germany]. Retrieved 2015-06-13.</ref><ref>[https://web.archive.org/web/20120502004731/http://news.chaobuoisang.net/school-in-berlin-maintains-vietnamese-language-197390.htm School in Berlin maintains Vietnamese language]. Retrieved 2015-06-13.</ref><ref>{{Citation |last=Blanc |first=Marie-Eve |title=Encyclopedia of Diasporas: Immigrant and Refugee Cultures Around the World |date=2004 |pages=1162 |editor-last=Ember |editor-first=Carol |contribution=Vietnamese in France |contribution-url=https://books.google.com/books?id=7QEjPVyd9YMC&pg=PA1162 |publisher=Springer |isbn=978-0-306-48321-9}}</ref>

==Phonology==
{{Main|Vietnamese phonology}}

===Vowels===
Vietnamese has a large number of [[vowel]]s. Below is a [[vowel diagram]] of Vietnamese from Hanoi (including [[centering diphthong]]s):

:{| class="wikitable" style="text-align: center;"
|-
! &nbsp;
! [[Front vowel|Front]]
! [[Central vowel|Central]]
! [[Back vowel|Back]]
|-
! [[Centering diphthong|Centering]]
| ia/iê {{IPA|[iə̯]}}
| ưa/ươ {{IPA|[ɨə̯]}}
| ua/uô {{IPA|[uə̯]}}
|-
! [[Close vowel|Close]]
| i/y {{IPA|[i]}}
| ư {{IPA|[ɨ]}}
| u {{IPA|[u]}}
|-
! [[Close-mid vowel|Close-mid]]/<br />[[Mid vowel|Mid]]
| ê {{IPA|[e]}}
| ơ {{IPA|[əː]}}<br />â {{IPA|[ə]}} 
| ô {{IPA|[o]}}
|-
! [[Open-mid vowel|Open-mid]]/<br />[[Open vowel|Open]]
|e {{IPA|[ɛ]}}
| a {{IPA|[aː]}}<br />ă {{IPA|[a]}}
| o {{IPA|[ɔ]}}
|}

Front and central vowels (i, ê, e, ư, â, ơ, ă, a) are [[Roundedness|unrounded]], whereas the back vowels (u, ô, o) are rounded. The vowels â {{IPA|[ə]}} and ă {{IPA|[a]}} are pronounced very short, much shorter than the other vowels. Thus, ơ and â are basically pronounced the same except that ơ {{IPA|[əː]}} is of normal length while â {{IPA|[ə]}} is short – the same applies to the vowels long a {{IPA|[aː]}} and short ă {{IPA|[a]}}.<ref group="lower-alpha">There are different descriptions of Hanoi vowels. Another common description is that of {{harv|Thompson|1991}}:

:{| class="wikitable" style="text-align: center;"
|-
! rowspan="2" |
! rowspan="2" | [[Front vowel|Front]]
! rowspan="2" | [[Central vowel|Central]]
! colspan="2" | [[Back vowel|Back]]
|-
! unrounded
! rounded
|-
! [[Centering diphthong|Centering]]
| ia~iê {{IPA|[iə̯]}}
|
| ưa~ươ {{IPA|[ɯə̯]}}
| ua~uô {{IPA|[uə̯]}}
|-
! [[Close vowel|Close]]
| i {{IPA|[i]}}
|
| ư {{IPA|[ɯ]}}
| u {{IPA|[u]}}
|-
! [[Close-mid vowel|Close-mid]]
| ê {{IPA|[e]}}
|
| ơ {{IPA|[ɤ]}}
| ô {{IPA|[o]}}
|-
! [[Open-mid vowel|Open-mid]]
| e {{IPA|[ɛ]}}
| ă {{IPA|[ɐ]}}
| â {{IPA|[ʌ]}}
| o {{IPA|[ɔ]}}
|-
! [[Open vowel|Open]]
|
| a {{IPA|[a]}}
| colspan="2" |
|}

This description distinguishes four degrees of vowel height and a rounding contrast (rounded vs. unrounded) between back vowels. The relative shortness of ''ă'' and ''â'' would then be a secondary feature. Thompson describes the vowel ''ă'' {{IPA|[ɐ]}} as being slightly higher ([[Near-open vowel|upper low]]) than ''a'' {{IPA|[a]}}.</ref>

The centering diphthongs are formed with only the three high vowels (i, ư, u). They are generally spelled as ia, ưa, ua when they end a word and are spelled iê, ươ, uô, respectively, when they are followed by a consonant.

In addition to single vowels (or [[monophthong]]s) and centering diphthongs, Vietnamese has closing [[diphthong]]s{{efn|In Vietnamese, diphthongs are ''âm đôi''.}} and [[triphthong]]s. The closing diphthongs and triphthongs consist of a main vowel component followed by a shorter semivowel [[offglide]] {{IPA|/j/}} or {{IPA|/w/}}.<ref group="lower-alpha">The closing diphthongs and triphthongs as described by Thompson can be compared with the description above:

:{| class="wikitable" style="text-align: center;"
|-
!&nbsp;
! colspan="2"| {{IPA|/w/}} offglide
! colspan="2"| {{IPA|/j/}} offglide
|-
! [[Centering diphthong|Centering]]
| iêu {{IPA|[iə̯w]}}
| ươu {{IPA|[ɯə̯w]}}
| ươi {{IPA|[ɯə̯j]}}
| uôi {{IPA|[uə̯j]}}
|-
! [[Close vowel|Close]]
| iu {{IPA|[iw]}}
| ưu {{IPA|[ɯw]}}
| ưi {{IPA|[ɯj]}}
| ui {{IPA|[uj]}}
|-
! [[Close-mid vowel|Close-mid]]
| êu {{IPA|[ew]}}
| rowspan="2"| –<br />âu {{IPA|[ʌw]}}
| rowspan="2"| ơi {{IPA|[ɤj]}}<br />ây {{IPA|[ʌj]}}
| ôi {{IPA|[oj]}}
|-
! [[Open-mid vowel|Open-mid]]
| eo {{IPA|[ɛw]}}
| oi {{IPA|[ɔj]}}
|-
! [[Open vowel|Open]]
| &nbsp;
| ao {{IPA|[aw]}}<br />au {{IPA|[ɐw]}}
| ai {{IPA|[aj]}}<br />ay {{IPA|[ɐj]}}
| &nbsp;
|}
</ref> There are restrictions on the high offglides: {{IPA|/j/}} cannot occur after a front vowel (i, ê, e) nucleus and {{IPA|/w/}} cannot occur after a back vowel (u, ô, o) nucleus.{{efn|The lack of diphthong consisting of a ''ơ'' + back offglide (i.e., {{IPA|[əːw]}}) is an apparent gap.}}

:{| class="wikitable" style="text-align: center;"
|-
! rowspan="2"|&nbsp;
! colspan="2"| {{IPA|/w/}} offglide
! colspan="2"| {{IPA|/j/}} offglide
|-
! [[Front vowel|Front]]
! colspan="2"| [[Central vowel|Central]]
! [[Back vowel|Back]]
|-
! [[Centering diphthong|Centering]]
| iêu {{IPA|[iə̯w]}}
| ươu {{IPA|[ɨə̯w]}}
| ươi {{IPA|[ɨə̯j]}}
| uôi {{IPA|[uə̯j]}}
|-
! [[Close vowel|Close]]
| iu {{IPA|[iw]}}
| ưu {{IPA|[ɨw]}}
| ưi {{IPA|[ɨj]}}
| ui {{IPA|[uj]}}
|-
! [[Close-mid vowel|Close-mid]]/<br />[[Mid vowel|Mid]]
| êu {{IPA|[ew]}}
| –<br />âu{{IPA|[əw]}}
| ơi {{IPA|[əːj]}}<br />ây {{IPA|[əj]}}
| ôi {{IPA|[oj]}}
|-
! [[Open-mid vowel|Open-mid]]/<br />[[Open vowel|Open]]
| eo {{IPA|[ɛw]}}
| ao {{IPA|[aːw]}}<br />au {{IPA|[aw]}}
| ai {{IPA|[aːj]}}<br />ay {{IPA|[aj]}}
| oi {{IPA|[ɔj]}}
|}

The correspondence between the orthography and pronunciation is complicated. For example, the offglide {{IPA|/j/}} is usually written as ''i''; however, it may also be represented with ''y''. In addition, in the diphthongs {{IPA|[āj]}} and {{IPA|[āːj]}} the letters ''y'' and ''i'' also indicate the pronunciation of the main vowel: ay = ă + {{IPA|/j/}}, ai = a + {{IPA|/j/}}. Thus, ''tay'' "hand" is {{IPA|[tāj]}} while ''tai'' "ear" is {{IPA|[tāːj]}}. Similarly, u and o indicate different pronunciations of the main vowel: au = ă + {{IPA|/w/}}, ao = a + {{IPA|/w/}}. Thus, ''<span lang="vi" dir="ltr">thau</span>'' "brass" is {{IPA|[tʰāw]}} while ''<span lang="vi" dir="ltr">thao</span>'' "raw silk" is {{IPA|[tʰāːw]}}.

===Consonants===
The consonants that occur in Vietnamese are listed below in the [[Vietnamese orthography]] with the phonetic pronunciation to the right.

:{| class=wikitable style=text-align:center
|-
! colspan=2|
! [[Labial consonant|Labial]]
! [[Dental consonant|Dental]]/<br />[[Alveolar consonant|Alveolar]]
! [[Retroflex]]
! [[Palatal consonant|Palatal]]
! [[Velar consonant|Velar]]
! [[Glottal consonant|Glottal]]
|-
! colspan=2| [[Nasal stop|Nasal]]
| m {{IPA|[m]}}
| n {{IPA|[n]}}
|
| nh {{IPA|[ɲ]}}
| ng/ngh {{IPA|[ŋ]}}
|
|-
! rowspan=3| [[Stop consonant|Stop]]
! <small>[[tenuis consonant|tenuis]]</small>
| p {{IPA|[p]}}
| t {{IPA|[t]}}
| tr {{IPA|[ʈ]}}
| ch {{IPA|[c]}}
| c/k/q {{IPA|[k]}}
|
|-
! <small>[[Aspirated consonant|aspirated]]</small>
|
| th {{IPA|[tʰ]}}
|
|
|
|
|-
! <small>[[Implosive consonant|implosive]]</small>
| b {{IPAblink|ɓ}}
| đ {{IPAblink|ɗ}}
|
|
|
|
|-
! rowspan=2| [[Fricative]]
! <small>[[Voicelessness|voiceless]]</small>
| ph {{IPA|[f]}}
| x {{IPA|[s]}}
| s {{IPA|[ʂ~s]}}
|
| kh {{IPA|[x~kʰ]}}
| h {{IPA|[h]}}
|-
! <small>[[Voice (phonetics)|voiced]]</small>
| v {{IPA|[v]}}
| d/gi {{IPA|[z~j]}}
|
|
| g/gh {{IPA|[ɣ]}}
|
|-
! colspan=2| [[Approximant]]
|
| l {{IPA|[l]}}
|
| y/i {{IPA|[j]}}
| u/o {{IPA|[w]}}
|
|-
! colspan=2| [[Rhotic consonant|Rhotic]]
|
| colspan=2| r {{IPA|[r]}}
|
|
|
|}

Some consonant sounds are written with only one letter (like "p"), other consonant sounds are written with a [[Digraph (orthography)|digraph]] (like "ph"), and others are written with more than one letter or digraph (the velar stop is written variously as "c", "k", or "q"). In some cases, they are based on their Middle Vietnamese pronunciation; since that period, ''ph'' and ''kh'' (but not ''th'') have evolved from aspirated stops into fricatives (like Greek [[phi]] and [[chi (letter)|chi]]), while ''d'' and ''gi'' have collapsed and converged together (into /z/ in the north and /j/ in the south).

Not all dialects of Vietnamese have the same consonant in a given word (although all dialects use the same spelling in the written language). See the [[#Language variation|language variation section]] for further elaboration.

Syllable-final orthographic ''ch'' and ''nh'' in Vietnamese has had different analyses. One analysis has final ''ch'', ''nh'' as being [[phoneme]]s {{IPA|/c/, /ɲ/}} contrasting with syllable-final ''t'', ''c'' {{IPA|/t/, /k/}} and ''n'', ''ng'' {{IPA|/n/, /ŋ/}} and identifies final ''ch'' with the syllable-initial ''ch'' {{IPA|/c/}}. The other analysis has final ''ch'' and ''nh'' as predictable [[allophonic]] variants of the velar [[phoneme]]s {{IPA|/k/}} and {{IPA|/ŋ/}} that occur after the upper front vowels ''i'' {{IPA|/i/}} and ''ê'' {{IPA|/e/}}; although they also occur after ''a'', but in such cases are believed to have resulted from an earlier ''e'' {{IPA|/ɛ/}} which diphthongized to ''ai'' (cf. ''ach'' from ''aic'', ''anh'' from ''aing''). (See [[Vietnamese phonology#Analysis of final ch.2C nh|Vietnamese phonology: Analysis of final ''ch'', ''nh'']] for further details.)

===Tones===
[[File:Vietnamese tone northern.svg|thumb|upright=1.6|Pitch contours and duration of the six Northern Vietnamese tones as spoken by a male speaker (not from Hanoi). [[Fundamental frequency]] is plotted over time. From Nguyễn & Edmondson (1998).]]

Each Vietnamese syllable is pronounced with one of six inherent [[Tone (linguistics)|tone]]s,{{efn|Tone is called {{lang|vi|thanh điệu}} or {{lang|vi|thanh}} in Vietnamese. Tonal language in Vietnamese translates to {{lang|vi|ngôn ngữ âm sắc}}.}} centered on the main vowel or group of vowels. Tones differ in:
* length (duration)
* [[pitch contour]] (i.e. pitch melody)
* pitch height
* [[phonation]]

Tone is indicated by diacritics written above or below the vowel (most of the tone diacritics appear above the vowel; except the ''<span lang="vi" dir="ltr">nặng</span>'' tone dot diacritic goes below the vowel).{{efn|The name of each tone has the corresponding tonal diacritic on the vowel.}} The six tones in the northern varieties (including Hanoi), with their self-referential Vietnamese names, are:

{| class="wikitable"
|-
! Name and meaning
! Description
!Contour
! Diacritic
! Example
! Sample vowel
!Unicode
|-
| '''''ngang''' &nbsp;'' 'level'
| mid level
|˧
| align="center" | <small>(no mark)</small>
| ''ma'' &nbsp;'ghost'
| align="center" | ''{{Audio|Vi ngang tone.ogg|a}}''
|
|-
| '''''huyền''' &nbsp;'' 'deep'
| low falling (often breathy)
|˨˩
| align="center" | {{IPA|◌̀}} ([[grave accent]])
| ''mà'' &nbsp;'but'
| align="center" | ''{{Audio|Vi huyen tone.ogg|à}}''
|U+0340 or U+0300
|-
| '''''sắc''' &nbsp;'' 'sharp'
| high rising
|˧˥
| align="center" | {{IPA|◌́}} ([[acute accent]])
| ''má'' &nbsp;'cheek, mother (southern)'
| align="center" | ''{{Audio|Vi sac tone.ogg|á}}''
|U+0341 or U+0301
|-
| '''''hỏi''' &nbsp;'' 'questioning'
| mid dipping-rising
|˧˩˧
| align="center" | {{IPA|◌̉}} ([[hook above]])
| ''mả'' &nbsp;'tomb, grave'
| align="center" | ''{{Audio|Vi hoi tone.ogg|ả}}''
|U+0309
|-
| '''''ngã''' &nbsp;'' 'tumbling'
| creaky high breaking-rising
|˧ˀ˦˥
| align="center" | {{IPA|◌̃}} ([[tilde]])
| ''mã'' &nbsp;'horse (Sino-Vietnamese), code'
| align="center" | ''{{Audio|Vi nga tone.ogg|ã}}''
|U+0342 or U+0303
|-
| '''''nặng''' &nbsp;'' 'heavy'
| creaky low falling constricted (short length)
|˨˩ˀ
| align="center" | {{IPA|◌̣}} ([[dot (diacritic)|dot below]])
| ''mạ'' &nbsp;'rice seedling'
| align="center" | ''{{Audio|Vi nang tone.ogg|ạ}}''
|U+0323
|}

Other dialects of Vietnamese may have fewer tones (typically only five).

{| class="wikitable"
|+ Tonal differences of three speakers as reported in Hwa-Froelich & Hodson (2002).<ref>Deborah, H.-F., W., H. B., & T., E. H. (2002). Characteristics of Vietnamese Phonology. American Journal of Speech-Language Pathology, 11(3), 264–273. https://doi.org/10.1044/1058-0360(2002/031)</ref> The curves represent temporal pitch variation while two sloped lines (//) indicates a [[glottal stop]].
|-
! Tone !! Northern dialect !! Southern dialect !! Central dialect
|-
| ''Ngang (a)''|| [[File:Vietnamese-tone-ngang-northern.png|30px]] || [[File:Vietnamese-tone-ngang-southern.png|30px]] || [[File:Vietnamese-tone-ngang-central.png|32px]]
|-
| ''Huyền (à)''|| [[File:Vietnamese-tone-huyen-northern.png|30px]] || [[File:Vietnamese-tone-huyen-southern.png|30px]] || [[File:Vietnamese-tone-huyen-central.png|30px]]
|-
| ''Sắc (á)''|| [[File:Vietnamese-tone-sac-northern.png|x30px]] || [[File:Vietnamese-tone-sac-southern.png|x30px]] || [[File:Vietnamese-tone-sac-central.png|x20px]]
|-
| ''Hỏi (ả)''|| [[File:Vietnamese-tone-hoi-northern.png|60px]] || [[File:Vietnamese-tone-hoi-southern.png|60px]] || [[File:Vietnamese-tone-hoi-central.png|30px]]
|-
| ''Ngã (ã)''|| [[File:Vietnamese-tone-nga-northern.png|50px]] || [[File:Vietnamese-tone-nga-southern.png|60px]] || [[File:Vietnamese-tone-nga-central.png|30px]]
|-
| ''Nặng (ạ)''|| [[File:Vietnamese-tone-nang-northern.png|30px]] || [[File:Vietnamese-tone-nang-southern.png|35px]] || [[File:Vietnamese-tone-nang-central.png|30px]]
|}

In Vietnamese poetry, tones are classed into two groups: ([[tone pattern]])

{| class="wikitable"
! Tone group
! Tones within tone group
|-
| ''bằng'' "level, flat"
| ''ngang'' and ''huyền''
|-
| ''trắc'' "oblique, sharp"
| ''sắc'', ''hỏi'', ''ngã'', and ''nặng''
|}

Words with tones belonging to a particular tone group must occur in certain positions within the poetic verse.

[[Catholic Church in Vietnam|Vietnamese Catholics]] practice a distinctive style of prayer recitation called {{lang|vi|[[đọc kinh]]}}, in which each tone is assigned a specific note or sequence of notes.

==== Old tonal classification ====
Before Vietnamese switched from a Chinese-based script to a Latin-based script, Vietnamese had used the traditional Chinese system of classifying tones. Using this system, Vietnamese has 8 tones, but modern linguists only count 6 phonemic tones.

Vietnamese tones were classified into two main groups, ''bằng'' (平; 'level tones') and ''trắc'' (仄; 'sharp tones'). Some tones such as ''ngang'' belong to the ''bằng'' group, while others such as ''ngã'' belong to the ''trắc'' group. Then, these tones were further divided in several other categories: ''bình'' (平; 'even'), ''thượng'' (上; 'rising'), ''khứ'' (去; 'departing'), and ''nhập'' (入; 'entering').

''Sắc'' and ''nặng'' are counted twice in the system, once in ''khứ'' (去; 'departing') and again in ''nhập'' (入; 'entering'). The reason for the extra two tones is that syllables ending in the stops /p/, /t/, /c/ and /k/ are treated as having entering tones, but phonetically they are exactly the same.

The tones in the old classification were called ''Âm bình'' 陰平 (''ngang''), ''Dương bình'' 陽平 (''huyền''), ''Âm thượng'' 陰上 (''hỏi''), ''Dương thượng'' 陽上 (''ngã''), ''Âm khứ'' 陰去 (''sắc''; for words that do not end in /p/, /t/, /c/ and /k/), ''Dương khứ'' 陽去 (''nặng''; for words that do not end in /p/, /t/, /c/ and /k/), ''Âm nhập'' 陰入 (''sắc''; for words that do end in /p/, /t/, /c/ and /k/), and ''Dương nhập'' 陽入 (''nặng''; for words that do end in /p/, /t/, /c/ and /k/).
{| class="wikitable"
|+
! colspan="2" |Traditional tone category
!Traditional tone name
!Modern tone name
!Example
|-
| rowspan="2" |'''''bằng'' 平 ''<nowiki/>'<nowiki/>''level''<nowiki/>''''''
| rowspan="2" |'''''bình'' 平 ''<nowiki/>'<nowiki/>''even''<nowiki/>''''''
|''Âm bình'' 陰平
|''ngang''
|ma 'ghost'
|-
|''Dương bình'' 陽平
|''huyền''
|mà 'but'
|-
| rowspan="6" |'''''trắc'' 仄 ''<nowiki/>'<nowiki/>''sharp''<nowiki/>''''''
| rowspan="2" |'''''thượng'' 上 ''<nowiki/>'<nowiki/>''rising''<nowiki/>''''''
|''Âm thượng'' 陰上
|''hỏi''
|rể 'son-in-law; groom'
|-
|''Dương thượng'' 陽上
|''ngã''
|rễ 'root'
|-
| rowspan="2" |'''''khứ'' 去 ''<nowiki/>'<nowiki/>''departing''<nowiki/>''''''
|''Âm khứ'' 陰去
|''sắc''
|lá 'leaf'
|-
|''Dương khứ'' 陽去
|''nặng''
|lạ 'strange'
|-
| rowspan="2" |'''''nhập'' 入 ''<nowiki/>'<nowiki/>''entering''<nowiki/>''''''
||''Âm nhập'' 陰入
|''sắc''
|mắt 'eye'
|-
|''Dương nhập'' 陽入
|''nặng''
|mặt 'face'
|}

==Grammar==
{{Main|Vietnamese grammar|Vietnamese morphology}}

Vietnamese, like Thai and many languages in Southeast Asia, is an [[analytic language]]. Vietnamese does not use [[morphology (linguistics)|morphological]] marking of [[Grammatical case|case]], [[grammatical gender|gender]], [[grammatical number|number]] or [[grammatical tense|tense]] (and, as a result, has no [[finite verb|finite]]/[[Non-finite verb|nonfinite]] distinction).{{efn|Comparison note: As such its grammar relies on word order and sentence structure rather than morphology (in which word changes through [[inflection]]). Whereas European languages tend to use morphology to express tense, Vietnamese uses [[grammatical particles]] or syntactic constructions.}} Also like other languages in the region, Vietnamese syntax conforms to [[subject–verb–object]] [[word order]], is [[head-initial]] (displaying modified-[[Grammatical modifier|modifier]] ordering), and has a noun [[Classifier (linguistics)|classifier]] system. Additionally, it is [[pro-drop]], [[wh-in-situ]], and allows [[verb serialization]].

Some Vietnamese sentences with English word [[Interlinear gloss|glosses]] and translations are provided below.

{{interlinear|indent=2|lang=vi
|Minh là {giáo viên}
|Minh BE teacher.
|"Minh is a teacher."}}

{{interlinear|indent=2|lang=vi
|Trí 13 tuổi
|Trí 13 age
|"Trí is 13 years old,"}}

{{interlinear|indent=2|lang=vi
|Mai {có vẻ} là {sinh viên} hoặc {học sinh}.
|Mai seem BE {student (college)} or {student (under-college)}
|"Mai seems to be a college or high school student."}}

{{interlinear|indent=2|lang=vi
|Tài đang nói.
|Tài PRES.CONT talk
|"Tài is talking."}}

{{interlinear|indent=2|lang=vi
|Giáp rất cao.
|Giáp INT tall
|"Giáp is very tall."}}

{{interlinear|indent=2|lang=vi
|Người đó là anh của nó.
|person that.DET BE {older brother} POSS 3.PRO
|"That person is his/her brother."}}

{{interlinear|indent=2|lang=vi
|Con chó này chẳng {bao giờ} sủa cả.
|CL dog DET NEG ever bark all
|"This dog never barks at all."}}

{{interlinear|indent=2|lang=vi
|Nó chỉ ăn cơm {Việt Nam} thôi.
|3.PRO just eat rice.FAM Vietnam only
|"He/she/it only eats Vietnamese rice (or food, especially spoken by the elderly)."}}

{{interlinear|indent=2|lang=vi
|Tôi thích con ngựa đen.
|1.PRO like CL horse black
|"I like the black horse."}}

{{interlinear|indent=2|lang=vi
|Tôi thích cái con ngựa đen đó.
|1.PRO like FOC CL horse black DET
|"I like that black horse."}}

{{interlinear|indent=2|lang=vi
|Hãy {ở lại} đây ít phút {cho tới} khi tôi quay lại.
|HORT stay here few minute until when 1.PRO turn again
|"Please stay here for a few minutes until I return."}}

==Lexicon==
[[File:Ethnolinguistic Groups of Mainland Southeast Asia.png|thumb|Ethnolinguistic Groups of Mainland Southeast Asia]]
[[File:VietnameseVocabComparsion.png|thumb|A comparison between Sino-Vietnamese (left) vocabulary with Mandarin and Cantonese pronunciations below and native Vietnamese vocabulary (right).]]

===Austroasiatic origins===
Many early studies hypothesized Vietnamese language-origins to have been either [[Kra-Dai languages|Kra-Dai]], [[Sino-Tibetan languages|Sino-Tibetan]], or [[Austroasiatic languages|Austroasiatic]]. Austroasiatic origins are so far the most tenable to date, with some of the oldest words in Vietnamese being [[Austroasiatic languages|Austroasiatic]] in origin.<ref name="Haudricourt 2017 122–128"/><ref>{{Cite journal|last=Alves|first=Mark|date=2006-02-01|title=Linguistic Research on the Origins of the Vietnamese Language: An Overview|url=https://www.researchgate.net/publication/249988619|journal=Journal of Vietnamese Studies|volume=1|issue=1–2|pages=104–130|doi=10.1525/vs.2006.1.1-2.104}}</ref>

=== Chinese contact===
[[File:Phở.png|thumb|upright=0.5|Old Nôm character for rice noodle soup "phở". The character [[⽶|米]] on the left means "rice" whilst the character on the right "頗" was used to indicate the sound of the word (''[[Pho|phở]]'').]]
Although Vietnamese roots are classified as Austroasiatic, Vietic, and Viet-Muong, [[language contact]] with Chinese heavily influenced the Vietnamese language, causing it to diverge from [[Viet-Muong]] around the 10th to 11th century and become the Vietnamese we know today. For instance, the Vietnamese word ''quản lý,'' meaning "management" (noun) or "manage" (verb), likely descended from the same word as ''guǎnlǐ'' ({{lang|zh|管理}}) in Chinese (also ''kanri'' ({{lang|ja|管理}}, {{lang|ja|かんり}}) in Japanese and ''gwalli'' (''gwan+ri''; {{Korean|hangul=관리|hanja=管理}}) in Korean). Instances of Chinese contact include the historical [[Nam Việt]] (aka [[Nanyue]]) as well as other periods of influence. Besides English and French, which have made some contributions to the Vietnamese language, Japanese loanwords into Vietnamese are also a more recently studied phenomenon.

Modern linguists describe modern Vietnamese having lost many [[Proto-Mon–Khmer language|Proto-Austroasiatic]] phonological and morphological features that original Vietnamese had.<ref>{{Cite journal|last=LaPolla|first=Randy J.|date=2010|title="Language Contact and Language Change in the History of the Sinitic Languages."|url=|journal=Procedia - Social and Behavioral Sciences|volume=2|issue=5|pages=6858–6868|doi=10.1016/j.sbspro.2010.05.036}}</ref> The Chinese influence on Vietnamese corresponds to various periods when Vietnam was under [[Vietnam under Chinese rule|Chinese rule]] and subsequent influence after Vietnam became independent. Early linguists thought that this meant the Vietnamese lexicon had only two influxes of Chinese words, one stemming from the period under actual Chinese rule and a second from afterwards. These words are grouped together as [[Sino-Vietnamese vocabulary]].

However, according to linguist John Phan, “Annamese Middle Chinese” was already used and spoken in the [[Red River (Asia)|Red River]] Valley by the 1st century CE, and its vocabulary significantly fused with the co-existing Proto-Viet-Muong language, the immediate ancestor of Vietnamese. He lists three major classes of Sino-Vietnamese borrowings:<ref>{{Cite web|last=Phan|first=John|date=2013-01-28|title=Lacquered Words: The Evolution Of Vietnamese Under Sinitic Influences From The 1St Century Bce Through The 17Th Century Ce|url=https://ecommons.cornell.edu/handle/1813/33867|language=en-US}}</ref><ref>{{Cite web|author1=Phan, John D. |author2=de Sousa, Hilário|date=2016|title=(Paper presented at the International workshop on the history of Colloquial Chinese – written and spoken, Rutgers University, New Brunswick NJ, 11–12 March 2016.)|url=http://hilario.bambooradical.com/downloadables/Phan-de-Sousa-2016-03-11-Rutgers-Southwester-Middle-Chinese.pptx.pdf|access-date=|website=}}</ref><ref>{{Cite journal|last=Phan|first=John|date=2010|title="Re-Imagining 'Annam': A New Analysis of Sino–Viet–Muong Linguistic Contact"|url=|journal=Chinese Southern Diaspora Studies|volume=4|pages=3–24|via=}}</ref> Early [[Sino-Vietnamese vocabulary|Sino-Vietnamese]] ([[Han dynasty]] ca. 1st century CE and [[Jin dynasty (266–420)|Jin dynasty]] ca. 4th century CE), Late Sino-Vietnamese ([[Tang dynasty]]), and Recent Sino-Vietnamese ([[Ming dynasty]] and afterwards)

=== French era ===
Vietnam became a French protectorate/colonial territory in 1883 (until the [[1954 Geneva Conference|Geneva Accords]] of 1954), which resulted in significant influence from [[French language in Vietnam|French]] into the Indochina region (Laos, Cambodia and Vietnam). Examples include:

''"Cà phê"'' in Vietnamese was derived from the French ''café'' (coffee). Yogurt in Vietnamese is ''"sữa chua"'' ({{lit|sour milk}}), but it is also calqued from French (''yaourt'') into Vietnamese (''da ua -'' /j/a ua). ''"Phô mai"'' (cheese) is from the French ''fromage''. [[Musical note]] was borrowed into Vietnamese as ''"nốt"'' or ''"nốt nhạc"'', from the French ''note de musique''. The Vietnamese term for [[steering wheel]] is ''"vô lăng"'', a partial derivation from the French ''volant directionnel''. A [[necktie]] (''cravate'' in French) is rendered into Vietnamese as ''"cà vạt"''.

In addition, modern Vietnamese pronunciations of French names correspond directly to the original French pronunciations (''"Pa-ri"'' for [[Paris]], ''"Mác-xây"'' for [[Marseille]], ''"Boóc-đô"'' for [[Bordeaux]], etc.), whereas pronunciations of other foreign names ([[Chinese language|Chinese]] excluded) are generally derived from English.

=== English ===
Some English words were incorporated into Vietnamese as [[loan words]] - such as "TV", borrowed as "tivi" or just TV, but still officially called ''truyền hình''. Some other borrowings are [[calque]]s, translated into Vietnamese. For example, 'software' is translated into "''phần mềm''" (literally meaning "soft part"). Some scientific terms, such as "biological cell", were derived from chữ Hán. For example, the word ''tế bào'' is {{lang|vi-hant|細胞}} in chữ Hán, whilst other scientific names such as "acetylcholine" are unaltered. Words like "peptide" may be seen as ''peptit''.

=== Japanese ===
Japanese loanwords are a more recently studied phenomenon, with a paper by Nguyễn & Lê (2020) classifying three waves of Japanese influence - with the first two waves being the principal influxes and the third wave coming from the Vietnamese who studied Japanese.<ref name=":0">{{Cite journal |last1=NGUYEN |first1=Danh Hoang Thanh |last2=LE |first2=Trang Thi Huyen |date=2020-03-31 |title=Japanese Loanwords Adopted into the Vietnamese Language by Vietnamese Students and Temporary Workers |url=https://doi.org/10.15026/94521 |journal=Asian and African Languages and Linguistics |language=en |volume=14 |pages=21 |doi=10.15026/94521}}</ref> The first wave consisted of Kanji words created by Japanese to represent Western concepts that were not readily available in Chinese or Japanese, where by the end of the 19th century they were imported to other Asian languages.<ref>{{Cite journal|last=Chung|date=2001|title=Some returned loans, Japanese loanwords in Taiwan Mandarin|journal=Language Change in East Asia|pages=161–179}}</ref> This first influx is called Sino-Vietnamese words of Japanese origins. For example, the Vietnamese term for "association club", ''câu lạc bộ,'' which was borrowed from Chinese ({{lang|zh|俱乐部}}, [[pinyin]]: ''jùlèbù'', [[jyutping]]: ''keoi1 lok6 bou6''), and then in turn from Japanese ([[kanji]]: {{lang|ja|倶楽部}}, [[katakana]]: {{lang|ja|クラブ}}, [[rōmaji]]: ''kurabu'') which came from the English "''club"'', resulting in indirect borrowing from Japanese.

The second wave was during the brief Japanese occupation of Vietnam from 1940 until 1945. However, Japanese cultural influence in Vietnam started significantly from the 1980s. This newer second wave of Japanese-origin loanwords is distinctive from the Sino-Vietnamese words of Japanese origin in that they were borrowed directly from Japanese. This vocabulary includes words representative of Japanese culture, such as ''kimono'', ''sumo'', ''samurai'', and ''bonsai'' from modified [[Hepburn romanization|Hepburn]] romanisation. These loanwords are coined as "new Japanese loanwords". A significant number of new Japanese loanwords were also of Chinese origin. Sometimes the same concept can be described using both Sino-Vietnamese words of Japanese origin (first wave) and new Japanese loanwords (second wave). For example, judo can be referred to as both ''judo'' and ''nhu đạo'', the Vietnamese reading of 柔道.<ref name=":0" />

=== Modern Chinese influence ===
Some words, such as ''lạp xưởng'' from 臘腸 (Chinese sausage), primarily keep to the [[Cantonese]] pronunciations, having been brought over by southern Chinese migrants, whereas in Hán-Việt, which has been described as being close to [[Middle Chinese]] pronunciation, it is actually pronounced ''lạp trường.'' However, the Cantonese term is the better-known name for [[Chinese sausage]] in Vietnam. Meanwhile, any new terms calqued from Chinese would be based on the [[Mandarin Chinese|Mandarin]] pronunciation. Additionally, in the southern provinces of Vietnam, the term ''[[:vi:Xúc xắc|xí ngầu]]'' can be used to refer to [[dice]], which may have derived from a [[Cantonese]] or [[Teochew dialect|Teochew]] idiom, "xập xí, xập ngầu" (十四, 十五, [[Sino-Vietnamese vocabulary|Sino-Vietnamese]]: ''thập tứ, thập ngũ''), literally "fourteen, fifteen" to mean 'uncertain'.

=== Pure Vietnamese words ===
Basic vocabulary in Vietnamese has Proto-Vietic origins. Vietnamese shares a large amount of vocabulary with the Mường languages, a close relative of the Vietnamese language.
[[File:渃𡽫.png|thumb|''nước non'' in the Vietnamese epic poem ''Đại Nam quốc sử diễn ca'' (大南國史演歌).]]
{| class="wikitable"
|+Basic lexemes in Vietnamese, Mường, [[May language|May]] and [[Munda languages|Munda]]
!English
!Vietnamese
!Mường
!May
!Comparative
!Proto-Vietic
|-
|zero
|''không''
|''không''
|''kħǒŋ''
|
|N/A, from [[Middle Chinese]] 空 /kʰuŋ/
|-
|one
|''một''
|''mốch, môch''
|''muc''
|''mɨy'' ([[Sora language|Sora]])
|*moːc
|-
|two
|''hai''
|''hal''
|''haːl''
|''bar'' ([[Santali language|Santali]])
|*haːr
|-
|three
|''ba''
|''pa''
|''pa''
|''pe'' ([[Santali language|Santali]])
|*pa
|-
|four
|''bốn''
|''pổn''
|''pon''
|''pon'' ([[Santali language|Santali]])
|*poːnʔ
|-
|five
|''năm''
|''đằm, đăm''
|''dăm''
|''mɔ̃ɽɛ̃'' ([[Santali language|Santali]])
|*ɗam
|-
|six
|''sáu''
|''khảu''
|''plǎų''
|''tuɾui'' ([[Korku language|Korku]])
|*p-ruːʔ
|-
|seven
|''bảy''
|''páy''
|''pǎi''
|''ei'' ([[Korku language|Korku]])
|*pəs
|-
|eight
|''tám''
|''thảm''
|''tʰam''
|''tʰam'' ([[Sora language|Sora]])
|*saːmʔ
|-
|nine
|''chín''
|''chỉn''
|''cin''
|''tin'' ([[Sora language|Sora]])
|*ciːnʔ
|-
|ten
|''mười''/''chục''
|''mườl''
|''mal''/''cuk''
|''gel'' ([[Sora language|Sora]])
|*maːl/*ɟuːk
|-
|you
|''mày''
|''mi''
|''ʔami''
|''amən'' ([[Sora language|Sora]])
|*miː
|-
|rain
|''mưa''
|''mưa''
|''kuma̤''
|''gama'' ([[Mundari language|Mundari]])
|*k-ma
|-
|wind
|''gió''
|''xỏ''
|''kuzɔ''
|''hɔjɔ'' ([[Mundari language|Mundari]])
|*k-jɔːʔ ~ *kʰjɔːʔ
|-
|mountain
|''rú''
|''khũ''
|''ɓlu''
|''bɘru'' ([[Sora language|Sora]])
|*b-ruːʔː
|-
|young
|''non''
|''non''
|''kunɔn''
|''kɔnɔn'' ([[Kharia language|Kharia]])
|*k-nɔːn
|-
|water
|''nác > nước''
|''đác''
|''dak''
|''daʔa'' ([[Sora language|Sora]])
|*ɗaːk
|-
|cold
|''lạnh''
|''lẽnh''
|''tabat/l͎uɓat ''
|''raŋga'' ([[Kharia language|Kharia]])
|*nl͎eŋ
|-
|smoke
|''mù''/''khói''
|''mù''/''khỏi''
|''hako''
|''poro'' ([[Sora language|Sora]])
|*ɓɔːjʔ
|-
|leaf
|''lá''
|''lả''
|''ʔula''
|''ola'' ([[Sora language|Sora]])
|*s-laːʔ
|-
|rice
|''gạo''
|''cảo''
|''tako''
|''caole'' ([[Santali language|Santali]])
|*r-koːʔ
|-
|meat
|''ñśic > thịt''
|''thit''
|''cit''
|''sissid'' ([[Sora language|Sora]])
|*-siːt
|-
|fish
|''cá''
|''cả''
|''ʔaka''
|''hako'' ([[Santali language|Santali]])
|*ʔa-kaːʔ
|-
|rat
|''chuột''
|''chuột''
|''kune''
|''gubu'' ([[Bonda language|Bonda]])
|*k-ɟɔːt
|-
|pig
|''cúi''
|''củi''
|''kul''
|''sukri'' ([[Santali language|Santali]])
|*kuːrʔ
|-
|fly (n.)
|''ruồi''
|''ròi''
|''muɽɔi̯''
|''aroi'' ([[Sora language|Sora]])
|*m-rɔːj
|-
|hold
|''cầm''
|''cầm''
|''kadap''
|''kum-si'' ([[Sora language|Sora]])
|*nkɘm
|-
|yawn
|''ngáp''
|''ngáp''
|''puŋoh''
|''aŋgɔ'b'' ([[Santali language|Santali]])
|*s-ŋaːp
|-
|to stab
|''chọc''
|''choc''
|''catʔ''
|''suj'' ([[Sora language|Sora]])
|*ncuk(i)
|-
|steal
|''trộm (đồ)''
|''lỗm''
|''lom''
|''kombro'' ([[Santali language|Santali]])
|*t.luːmʔ
|}

Other compound words, such as nước non (chữ Nôm: 渃𡽫, "country/nation", lit. "water and mountains"), appear to be of purely Vietnamese origin and used to be inscribed in chữ Nôm characters (compounded, self-coined Chinese characters) but are now written in the Vietnamese alphabet.

== Slang ==
Vietnamese [[slang]] (tiếng lóng) has changed over time. Vietnamese slang consists of pure Vietnamese words as well as words borrowed from other languages such as [[Mandarin Chinese|Mandarin]] or [[Indo-European languages]].<ref name=":02">{{Cite web|title=Tiếng lóng trên các phương tiện truyền thông hiện nay|url=http://khoavanhoc-ngonngu.edu.vn/en/uncategorised/4251-ting-long-tren-cac-phng-tin-truyn-thong-hin-nay.html|website=khoavanhoc-ngonngu.edu.vn}}</ref> It is estimated that Vietnamese slang originating from Mandarin accounts for a tiny proportion (4.6% of surveyed data in newspapers).<ref name=":02" /> On the other hand, slang originating from Indo-European languages accounts for a more significant proportion (12%) and is much more common in today's usage.<ref name=":02" /> Slang borrowed from these languages can be either [[transliteration|transliteral]] or [[vernacular]].<ref name=":02" /> Some examples:
{| class="wikitable"
|+
!Word
![[International Phonetic Alphabet|IPA]]
!Description
|-
|''Ex''
|{{IPA|/ɛk̚/, /ejk̚/}}
|a word borrowed from English used to describe an ex-lover, usually pronounced similarly to ''ếch'' ("frog"). This is an example of vernacular slang.<ref name=":02" />
|-
|''Sô''
|{{IPA|/ʂoː/}}
|a word derived from the English word "show''"'' which has the same meaning, usually paired with the word ''chạy'' ("to run") to make the phrase ''chạy sô'', which translates in English to "running shows", but its everyday use has the same connotation as "having to do a lot of tasks within a short amount of time". This is an example of transliteral slang.<ref name=":02" />
|}
With the rise of the Internet, new slang is generated and popularized through [[social media]]. This modern slang is commonly used in the younger generation's teenspeak in Vietnam. This recent slang is mostly pure Vietnamese, and almost all the words are [[homonym]]s or some form of [[Word play|wordplay]]. Some slang words may include [[profanity]] swear words ([[Pejorative|derogatory]]) or just a [[Play-on-words|play on words]].

Some examples with newer and older slang that originate from northern, central, or southern Vietnamese dialects include:
{| class="wikitable"
|+
!Word
!IPA
!Description
|-
|''vãi''
|{{IPA|/vǎːj/}}
|"Vãi" (predominately from northern Vietnamese) is a [[profanity]] word that can be a noun or a verb depending on the context. It refers to a female [[Buddhist temple]]-goer in its noun form and to "spilling something over" in its verb form. In slang terms, it is commonly used to emphasize an adjective or a verb - for example, ''ngon vãi'' ("very delicious"), ''sợ vãi'' ("very scary").<ref>{{Cite web|date=2020-07-18|title=Vãi là gì? Tại sao các bạn trẻ lại hay sử dụng từ này?|url=https://tbtvn.org/vai-la-gi-tai-sao-cac-ban-tre-lai-hay-su-dung-tu-nay/|website=tbtvn.org}}</ref> Similar uses to the [[profanity|expletive]] [[bloody]].
|-
|''trẻ trâu''
|{{IPA|/ʈɛ̌ːʈəw/}}
|A noun whose literal translation is "buffalo kid". It is usually used to describe younger children or people who behave like a child, like putting on airs and acting foolishly to attract other people's attention (with negative actions, words, and thoughts).<ref name=":22">{{Cite web|date=2016-06-25|title=10 từ lóng thường dùng của giới trẻ ngày nay|url=https://vnexpress.net/10-tu-long-thuong-dung-cua-gioi-tre-ngay-nay-3425491-p2.html|website=vnexpress.net}}</ref>
|-
|''gấu''
|{{IPA|/ɣə̆́w/}}
|A noun meaning "bear". It is also commonly used to refer to someone's lover.<ref name=":12">{{Cite web|date=2016-06-25|title=10 từ lóng thường dùng của giới trẻ ngày nay|url=https://vnexpress.net/10-tu-long-thuong-dung-cua-gioi-tre-ngay-nay-3425491.html|website=vnexpress.net}}</ref>
|-
|''gà''
|{{IPA|/ɣàː/}}
|A noun meaning "chicken". It is also commonly used to refer to someone's lack of ability to complete or compete in a task.<ref name=":22" />
|-
|''cá sấu''
|{{IPA|/káːʂə́w/}}
|A noun meaning "crocodile". It is also commonly used to refer to someone's lack of beauty. The word ''sấu'' can be pronounced similarly to ''xấu'' (ugly).<ref name=":12" />
|-
|''thả thính''
|{{IPA|/tʰǎːtʰíŋ̟/}}
|A verb used to describe the action of dropping roasted [[bran]] as bait for fish. Nowadays it is also used to describe the act of dropping hints to another person one is attracted to.<ref name=":12" />
|-
|''nha (and other variants)''
|{{IPA|/ɲaː/}}
|Similar to other particles (nhé, nghe, nhỉ, nhá), it can be used to end sentences. "Rửa chén, nhỉ" can mean "Wash the dishes... yeah?"<ref>{{Cite web|title=What is the difference between "nhé" and "nha, nghe, nhà, nhỉ" ? "nhé" vs "nha, nghe, nhà, nhỉ" ?|url=https://hinative.com/en-US/questions/5240316|access-date=2021-03-14|website=hinative.com|language=en|archive-date=2022-06-17|archive-url=https://web.archive.org/web/20220617072614/https://hinative.com/en-US/questions/5240316|url-status=dead}}</ref>
|-
|''dô (South) and dzô or zô (North)''
|{{IPA|/zo:/, /jow/}}
|[[Eye dialect]] of the word vô, meaning "in". Slogans when drinking at parties. Usually people in the south of Vietnam will pronounce it as "dô", but people in the north pronounce it as "dzô". The letter "z", which is not usually present in the Vietnamese alphabet, can be used for emphasis or for slang terms.<ref>{{Cite web|title=Vã mồ hôi "giải mã" tiếng lóng tuổi teen – Xã hội – VietNamNet|url=https://vietnamnet.vn/xahoi/201005/Va-mo-hoi-giai-ma-tieng-long-tuoi-teen-911455/index.htm?mode=mobile|access-date=2021-04-06|website=vietnamnet.vn}}</ref>
|-
|''lu bu, lu xu bu''
|{{IPA|/lu: bu:/}},
{{IPA|/lu: su: bu:/}}
|"Lu bu" (from southern Vietnamese) meaning busy. "Lu xu bu" meaning so busy at a particular task or activity that the person cannot do much else - e.g., ''quá lu bu'' (so busy).<ref>{{Cite web |date=2019-12-05 |title=What is the meaning of "tôi chóng mặt luôn, quá lu bu quá mệt (plz english)"? - Question about Vietnamese |url=https://hinative.com/questions/14944672 |access-date=2023-06-07 |website=HiNative |language=en}}</ref>
|}
Whilst older slang has been used by previous generations, the prevalence of modern slang used by young people in Vietnam (as teenspeak) has made conversations more difficult for older generations to understand. This has become subject for debate. Some believe that incorporating teenspeak or internet slang in daily conversation among teenagers will affect the formality and cadence of their general speech.<ref>{{Cite web|date=2018-12-07|title=Lo ngại thực trạng sử dụng ngôn ngữ mạng trong học sinh|url=https://baoninhbinh.org.vn/lo-ngai-thuc-trang-su-dung-ngon-ngu-mang-trong-hoc-sinh/d20181207091625582.htm|website=baoninhbinh.org.vn}}</ref> Others argue that it is not slang that is the problem, but rather the lack of communication techniques for the instant internet messaging era. They believe slang should not be dismissed, but instead, youth should be adequately informed to recognise when to use it and when it is inappropriate.

==Writing systems==
{{Main|History of writing in Vietnam|Vietnamese Braille}}
[[File:Tale of Kieu parallel text.svg|thumb|right|upright=1.5|The first two lines of the classic Vietnamese epic poem ''[[The Tale of Kieu|The Tale of Kiều]]'', written in the [[Chữ Nôm|Nôm script]] and the modern Vietnamese alphabet. Chinese characters representing Sino-Vietnamese words are shown in {{color|#1b9e77|green}}, characters borrowed for similar-sounding native Vietnamese words in {{color|#7570b3|purple}}, and invented characters in {{color|#d95f02|brown}}.]]
[[File:Nhật dụng thường đàm, p. 38.jpg|thumb|In the [[bilingual]] dictionary ''Nhật dụng thường đàm'' (1851), Chinese characters ({{lang|vi|chữ Nho}}) are explained in {{lang|vi|chữ Nôm}}.]]
[[File:Taberd dictionary.jpg|thumb|[[Jean-Louis Taberd]]'s dictionary ''Dictionarium anamitico-latinum'' (1838) represents Vietnamese (then Annamese) words in the Latin alphabet and {{lang|vi|chữ Nôm}}.]]
[[File:HoaloHaNoi070720091321.jpg|thumb|A sign at the [[Hỏa Lò Prison]] museum in Hanoi lists rules for visitors in both Vietnamese and English.]]

After ending a millennium of [[Vietnam under Chinese rule|Chinese rule]] in 939, the Vietnamese state adopted [[Literary Chinese]] (called {{lang|vi|văn ngôn}} {{linktext|lang=zh|文言}} or {{lang|vi|Hán văn}} {{linktext|lang=zh|漢文}} in Vietnamese) for official purposes.<ref>{{cite book | title = Asia's Orthographic Dilemma | surname = Hannas | given = Wm. C. | publisher = University of Hawaii Press | year = 1997 | isbn = 978-0-8248-1892-0 | pages = 78–79, 82 }}</ref>
Up to the late 19th century (except for two brief interludes), all formal writing, including government business, scholarship and formal literature, was done in Literary Chinese, written with [[Chinese characters]] ({{lang|vi|[[chữ Hán]]}}).{{sfn|Marr|1984|p=141}} Although the writing system is now mostly in [[Chữ Quốc ngữ|''chữ'' ''Quốc ngữ'']] ([[Latin script]]), Chinese script known as chữ Hán in Vietnamese as well as chữ Nôm (together, Hán-Nôm) is still present in such activities such as [[Vietnamese calligraphy]].

=== Chữ Nôm ===
{{main|Chữ Nôm}}
From around the 13th century, Vietnamese scholars used their knowledge of the Chinese script to develop the {{lang|vi|chữ Nôm}} ({{literal translation|Southern characters}}) script to record folk literature in Vietnamese. The script used Chinese characters to represent both borrowed [[Sino-Vietnamese vocabulary]] and native words with similar pronunciation or meaning. In addition, thousands of new compound characters were created to write Vietnamese words using a variety of methods, including [[phono-semantic compound]]s.{{sfn|DeFrancis|1977|p=24–26}}
For example, in the opening lines of the classic poem ''[[The Tale of Kieu|The Tale of Kiều]]'',
* the Sino-Vietnamese word {{lang|vi|mệnh}} 'destiny' was written with its original character {{linktext|lang=zh|命}};
* the native Vietnamese word {{lang|vi|ta}} 'our' was written with the character {{linktext|lang=zh|些}} of the homophonous Sino-Vietnamese word {{lang|vi|ta}} 'little, few; rather, somewhat';
* the native Vietnamese word {{lang|vi|năm}} 'year' was written with a new character 𢆥 that is compounded from {{linktext|lang=zh|南}} {{lang|vi|nam}} and {{linktext|lang=zh|年}} 'year'.
The oldest example of an early form of the {{lang|vi|Nôm}} is found in a list of names in the Tháp Miếu Temple Inscription, dating from the early 13th century AD.<ref name=Holcombe>{{Cite book |last=Holcombe |first=Charles |title=A History of East Asia: From the Origins of Civilization to the Twenty-First Century|publisher=Cambridge University Press |year=2017 |isbn=978-1107544895 |page=207}}</ref><ref name=Kornicki>{{Cite book |last=Kornicki |first=Peter |title=Languages, Scripts, and Chinese Texts in East Asia |publisher=Oxford University Press |year=2018 |isbn=978-0-192-51869-9|page=63}}</ref>
{{lang|vi|Nôm}} writing reached its zenith in the 18th century when many Vietnamese writers and poets composed their works in {{lang|vi|Nôm}}, most notably [[Nguyễn Du]] and [[Hồ Xuân Hương]] (dubbed "the Queen of Nôm poetry"). However, it was only used for official purposes during the brief [[Hồ dynasty|Hồ]] and [[Tây Sơn dynasty|Tây Sơn]] dynasties (1400–1406 and 1778–1802 respectively).{{sfn|DeFrancis|1977|pp=32, 38}}

A [[Catholic Church in Vietnam|Vietnamese Catholic]], [[Nguyễn Trường Tộ]], unsuccessfully petitioned the Court suggesting the adoption of a script for Vietnamese based on Chinese characters.{{sfn|DeFrancis|1977|pp=101–105}}{{sfn|Marr|1984|p=145}}

=== Vietnamese alphabet ===
{{main|Vietnamese alphabet}}
A [[romanization|romanisation]] of Vietnamese was codified in the 17th century by the Avignonese [[Society of Jesus|Jesuit]] missionary [[Alexandre de Rhodes]] (1591–1660), based on works of earlier [[Portuguese discoveries|Portuguese missionaries]], particularly [[Francisco de Pina]], Gaspar do Amaral and Antonio Barbosa.<ref name="Jacques 2002">{{cite book|last1=Jacques|first1=Roland|title=Portuguese Pioneers of Vietnamese Linguistics Prior to 1650 – Pionniers Portugais de la Linguistique Vietnamienne Jusqu'en 1650|date=2002|publisher=Orchid Press|location=Bangkok, Thailand|isbn=974-8304-77-9|language=en, fr}}</ref><ref name="Tran 2019">{{cite conference |url = https://www.academia.edu/41197889 |title = Từ Nước Mặn đến Roma: Những đóng góp của các giáo sĩ Dòng Tên trong quá trình La tinh hoá tiếng Việt ở thế kỷ 17 |last1 = Trần | first1 = Quốc Anh| last2 = Phạm | first2 = Thị Kiều Ly | date = October 2019 |publisher = Committee on Culture, [[Catholic Bishops' Conference of Vietnam]] |conference= Conference ''400 năm hình thành và phát triển chữ Quốc ngữ trong lịch sử loan báo Tin Mừng tại Việt Nam'' |location = Hochiminh City}}</ref>
It reflects a "Middle Vietnamese" dialect close to the Hanoi variety as spoken in the 17th century. Its vowels and final consonants correspond most closely to northern dialects while its initial consonants are most similar to southern dialects. (This is not unlike how [[English orthography]] is based on the Chancery Standard of [[Middle English#Late Middle English|Late Middle English]], with many spellings retained even after the [[Great Vowel Shift]].)

The Vietnamese alphabet contains 29 letters, supplementing the Latin alphabet with an additional consonant letter (''[[D with stroke|đ]]'') and 6 additional vowel letters (''ă'', ''â/ê/ô'', ''ơ'', ''ư'') formed with [[diacritic]]s. The Latin letters ''f'', ''j'', ''w'' and ''z'' are not used.<ref name=":1">{{Cite web |title=Alphabet {{!}} Vietnamese Typography |url=https://vietnamesetypography.com/alphabet/ |access-date=2023-06-24 |website=vietnamesetypography.com}}</ref><ref>{{Cite web|last=admin|date=2014-02-05|title=Vietnamese Language History|url=https://www.vietnam-culture.com/vietnamese-language-history.aspx|access-date=2021-01-30|website=Vietnamese Culture and Tradition|language=en-US}}</ref>
The script also represents additional [[phoneme]]s using ten [[Digraph (orthography)|digraphs]] (''ch'', ''gh'', ''gi'', ''kh'', ''ng'', ''nh'', ''ph'', ''qu'', ''th'', and ''tr'') and a single [[Trigraph (orthography)|trigraph]] (''ngh'').
Further diacritics are used to indicate the [[Tone (linguistics)|tone]] of each syllable:

{| class="wikitable"
|-
! Diacritic
! Vietnamese name and meaning
|-
| align="center" | <small>(no mark)</small>
| {{lang|vi|ngang}} 'level'
|-
| align="center" | {{IPA|◌̀}} ([[grave accent]])
| {{lang|vi|huyền}} 'deep'
|-
| align="center" | {{IPA|◌́}} ([[acute accent]])
| {{lang|vi|sắc}} 'sharp'
|-
| align="center" | {{IPA|◌̉}} ([[hook above]])
| {{lang|vi|hỏi}} 'questioning'
|-
| align="center" | {{IPA|◌̃}} ([[tilde]])
| {{lang|vi|ngã}} 'tumbling'
|-
| align="center" | {{IPA|◌̣}} ([[dot (diacritic)|dot below]])
| {{lang|vi|nặng}} 'heavy'
|}

Thus, it is possible for diacritics to be stacked e.g. ể, combining letter with diacritic, ê, with diacritic for tone, ẻ, to make ể.

Despite the missionaries' creation of the alphabetic script, {{lang|vi|chữ Nôm}} remained the dominant script in [[Catholic Church in Vietnam|Vietnamese Catholic]] literature for more than 200 years.<ref>{{cite book |last=Ostrowski |first=Brian Eugene |editor-last=Wilcox |editor-first=Wynn |title=Vietnam and the West: New Approaches |date=2010 |publisher=[[Cornell Southeast Asia Program#SEAP Publications|SEAP Publications]], Cornell University Press |location=Ithaca, New York |isbn=978-0-87727-782-8 |chapter= The Rise of Christian Nôm Literature in Seventeenth-Century Vietnam: Fusing European Content and Local Expression |pages=23, 38 }}</ref> Starting from the late 19th century, the Vietnamese alphabet ({{lang|vi|chữ Quốc ngữ}} or 'national language script') gradually expanded from its initial usage in Christian writing to become more popular among the general public.

The romanised script became predominant over the course of the early 20th century, when education became widespread and a simpler writing system was found to be more expedient for teaching and communication with the general population. The [[French Indochina|French colonial administration]] sought to eliminate Chinese writing, Confucianism, and other Chinese influences from Vietnam.{{sfn|Marr|1984|p=145}} French superseded Literary Chinese in administration. Vietnamese written with the alphabet became required for all public documents in 1910 by issue of a decree by the French Résident Supérieur of the protectorate of [[Tonkin]]. In turn, Vietnamese reformists and nationalists themselves encouraged and popularized the use of {{lang|vi|chữ Quốc ngữ}}. By the middle of the 20th century, most writing was done in {{lang|vi|chữ Quốc ngữ}}, which became the official script on independence.

Nevertheless, {{lang|vi|chữ Hán}} was still in use during the French colonial period and as late as [[World War II]] was still featured on banknotes,<ref>{{cite web |url=http://art-hanoi.com/collection/icpaper/p83.html |title=French Indochina 500 Piastres 1951 |website=art-hanoi.com}}</ref><ref>{{cite web |url=http://art-hanoi.com/collection/vnpaper/ho5d.html |title=North Vietnam 5 Dong 1946 |website=art-hanoi.com}}</ref> but fell out of official and mainstream use shortly thereafter. The education reform by [[North Vietnam]] in 1950 eliminated the use of {{lang|vi|chữ Hán}} and {{lang|vi|chữ Nôm}}.<ref>Vũ Thế Khôi (2009). [https://web.archive.org/web/20160914180432/http://www.vusta.vn/vi/news/Thong-tin-Su-kien-Thanh-tuu-KH-CN/Ai-buc-tu-chu-Han-Nom-31759.html "Ai “bức tử” chữ Hán-Nôm?"].</ref> Today, only a few scholars and some extremely elderly people are able to read {{lang|vi|chữ Nôm}} or use it in [[Vietnamese calligraphy]]. Priests of the [[Gin people|Jing]] minority in China (descendants of 16th-century migrants from Vietnam) use songbooks and scriptures written in {{lang|vi|chữ Nôm}} in their ceremonies.<ref>{{cite book |title=Encyclopedia of World Cultures, volume 6: Russia and Eurasia / China |editor1-given=Paul |editor1-surname=Friedrich |editor2-given=Norma |editor2-surname=Diamond |chapter=Jing |page=454 | publisher=G.K. Hall |location=New York |year=1994 |isbn=0-8161-1810-8 }}</ref>

===Computer support===
{{main|Vietnamese language and computers}}

The [[Unicode]] character set contains all Vietnamese characters and the Vietnamese currency symbol. On systems that do not support Unicode, many 8-bit Vietnamese [[code page]]s are available such as [[Vietnamese Standard Code for Information Interchange]] (VSCII) or [[Windows-1258]]. Where [[ASCII]] must be used, Vietnamese letters are often typed using the [[Vietnamese Quoted-Readable|VIQR]] convention, though this is largely unnecessary with the increasing ubiquity of Unicode. There are many software tools that help type Roman-script Vietnamese on English keyboards, such as [http://winvnkey.sf.net WinVNKey] and [https://www.unikey.org/ Unikey] on Windows, or [http://macvnkey.sf.net MacVNKey] on Macintosh, with popular methods of [https://tipsmake.com/encoding-of-vietnamese-typing-methods-telex-vni-and-viqr-on-unikey encoding] Vietnamese using Telex, VNI or VIQR input methods all included. [[Telex (input method)|Telex]] input method is often set as the default for many devices. Besides third-party software tools, operating systems such as [[Windows]] or [[macOS]] can also be installed with Vietnamese and Vietnamese keyboard, e.g. ''Vietnamese Telex'' in Microsoft Windows.

===Dates and numbers writing formats===
Vietnamese speak date in the format "[[day]] [[month]] [[year]]". Each month's name is just the ordinal of that month appended after the word ''tháng'', which means "month". Traditional Vietnamese, however, assigns other names to some months; these names are mostly used in the [[lunar calendar]] and in poetry.

{| class="wikitable"
|-
! rowspan="2" | English month name !! colspan="2" | Vietnamese month name
|-
! Gregorian calendar !! Traditional [[Vietnamese calendar|lunar calendar]]
|-
| January || Tháng một (1) || Tháng giêng
|-
| February || colspan="2" | Tháng hai (2)
|-
| March || colspan="2" | Tháng ba (3)
|-
| April || colspan="2" | Tháng tư (4)
|-
| May || colspan="2" | Tháng năm (5)
|-
| June || colspan="2" | Tháng sáu (6)
|-
| July || colspan="2" | Tháng bảy (7)
|-
| August || colspan="2" | Tháng tám (8)
|-
| September || colspan="2" | Tháng chín (9)
|-
| October || colspan="2" | Tháng mười (10)
|-
| November || Tháng mười một (11)
|Tháng một
|-
| December || Tháng mười hai (12) || Tháng chạp
|}

When written in the short form, "DD/MM/YYYY" is preferred.

''Example:''
*'''English:''' 28 March 2018
*'''Vietnamese long form:''' Ngày 28 tháng 3 năm 2018
*'''Vietnamese short form:''' 28/3/2018

The Vietnamese prefer writing numbers with a [[comma]] as the decimal separator in lieu of dots, and either spaces or dots to group the digits. An example is 1 629,15 (one thousand six hundred twenty-nine point one five). Because a comma is used as the decimal separator, a [[semicolon]] is used to separate two numbers instead.

==Literature==
{{main|Vietnamese literature}} 
''[[The Tale of Kieu|The Tale of Kiều]]'' is an epic narrative poem by the celebrated poet [[Nguyễn Du]], ({{vi-nom|{{linktext|阮|攸}}}}), which is often considered the most significant work of [[Vietnamese literature]]. It was originally written in chữ Nôm (titled {{lang|vi|Đoạn Trường Tân Thanh}} {{vi-nom|{{linktext|斷腸|新|聲}}}}) and is widely taught in Vietnam (in ''chữ Quốc ngữ'' transliteration).

==Language variation==
{{Original research section|date=April 2021}}
Currently the [[Nguồn language]] is considered by the Vietnamese government to be a dialect of Vietnamese, however it is also considered a separate Việt-Mường language or the southernmost dialect of Mường language. The Vietnamese language also has several [[mutual intelligibility|mutually intelligible]] regional varieties:{{efn|Sources on Vietnamese variation include: Alves (forthcoming), Alves & Nguyễn (2007), Emeneau (1947), Hoàng (1989), Honda (2006), Nguyễn, Đ.-H. (1995), Pham (2005), Thompson (1991[1965]), Vũ (1982), Vương (1981).}}

{| class="wikitable"
! Dialect region
! Localities
|-
| Northern Vietnamese dialects
| [[Northern Vietnam]]
|-
| Thanh Hóa dialect 
| [[Thanh Hóa Province|Thanh Hoá]] 
|-
| Central Vietnamese dialects
| [[Nghệ An Province|Nghệ An]], [[Hà Tĩnh Province|Hà Tĩnh]], [[Quảng Bình Province|Quảng Bình]], [[Quảng Trị Province|Quảng Trị]]
|-
| Huế dialect
| [[Huế]]
|-
| Southern Vietnamese dialects
| [[South Central Coast]], [[Central Highlands (Vietnam)|Central Highlands]] and [[Southern Vietnam]]
|}

Vietnamese has traditionally been divided into three dialect regions: North (45%), Central (10%), and South (45%). [[Michel Ferlus]] and Nguyễn Tài Cẩn found that there was a separate North-Central dialect for Vietnamese as well. The term ''Haut-Annam'' refers to dialects spoken from the northern Nghệ An Province to the southern (former) Thừa Thiên Province that preserve archaic features (like consonant clusters and undiphthongized vowels) that have been lost in other modern dialects.

The dialect regions differ mostly in their sound systems (see below) but also in vocabulary (including basic and non-basic vocabulary) and grammar.{{efn|Some differences in [[grammatical word]]s are noted in [[Vietnamese grammar#Demonstratives|Vietnamese grammar: Demonstratives]], [[Vietnamese grammar#Pronouns|Vietnamese grammar: Pronouns]].}} The North-Central and the Central regional varieties, which have a significant number of vocabulary differences, are generally less [[mutually intelligible]] to Northern and Southern speakers. There is less internal variation within the Southern region than the other regions because of its relatively late settlement by Vietnamese-speakers (around the end of the 15th century). The North-Central region is particularly conservative since its pronunciation has diverged less from Vietnamese orthography than the other varieties, which tend to merge certain sounds. Along the coastal areas, regional variation has been neutralized to a certain extent, but more mountainous regions preserve more variation. As for [[sociolinguistic]] attitudes, the North-Central varieties are often felt to be "peculiar" or "difficult to understand" by speakers of other dialects although their pronunciation fits the written language the most closely; that is typically because of various words in their vocabulary that are unfamiliar to other speakers (see the example vocabulary table below).
{{Listen
| header      = 
| type        = speech
| filename    = Universal declaration of human rights VN.ogg
| title       = The first article of the Universal Declaration of Human Rights 
| description = The first article of the Universal Declaration of Human Rights spoken by Nghiem Mai Phuong, native speaker of a northern variety.}}

The large movements of people between North and South since the mid-20th century has resulted in a sizable number of Southern residents speaking in the Northern accent/dialect and, to a greater extent, Northern residents speaking in the Southern accent/dialect. After the [[Geneva Conference (1954)|Geneva Accords of 1954]], which called for the [[Geneva Conference (1954)|temporary division of the country]], about a million northerners (mainly from Hanoi, [[Haiphong]], and the surrounding Red River Delta areas) moved south (mainly to [[Saigon]] and heavily to [[Biên Hòa]] and [[Vũng Tàu]] and the surrounding areas) as part of [[Operation Passage to Freedom]]. About 180,000 moved in the reverse direction (''Tập kết ra Bắc'', literally "go to the North".)

After the [[Fall of Saigon]] in 1975, Northern and North-Central speakers from the densely-populated Red River Delta and the traditionally-poorer provinces of Nghệ An, Hà Tĩnh, and Quảng Bình have continued to move south to look for better economic opportunities allowed by the new government's New Economic Zones, a program that lasted from 1975 to 1985.<ref name=Desbarats>{{cite web|last=Desbarats|first=Jacqueline|title=Repression in the Socialist Republic of Vietnam: Executions and Population Relocation|url=http://jim.com/repression.htm|work=Indochina report; no. 11|publisher=Executive Publications, Singapore 1987|access-date=28 November 2013|archive-date=17 February 2015|archive-url=https://web.archive.org/web/20150217064307/http://jim.com/repression.htm|url-status=dead}}</ref> The first half of the program (1975–1980) resulted in 1.3 million people sent to the New Economic Zones (NEZs), most of which were relocated to the southern half of the country in previously uninhabited areas, and 550,000 of them were Northerners.<ref name=Desbarats /> The second half (1981–1985) saw almost 1 million Northerners relocated to the New Economic Zones.<ref name=Desbarats /> Government and military personnel from Northern and North-Central Vietnam are also posted to various locations throughout the country that were often away from their home regions. More recently, the growth of the free market system has resulted in increased interregional movement and relations between distant parts of Vietnam through business and travel. The movements have also resulted in some blending of dialects and more significantly have made the Northern dialect more easily understood in the South and vice versa. Most Southerners, when singing modern/old popular Vietnamese songs or addressing the public, do so in the standardized accent if possible, which uses the Northern pronunciation. That is true in both Vietnam and overseas Vietnamese communities.

Modern Standard Vietnamese is based on the Hanoi dialect. Nevertheless, the major dialects are still predominant in their respective areas and have also evolved over time with influences from other areas. Historically, accents have been distinguished by how each region pronounces the letters ''d'' ({{IPA|[z]}} in the Northern dialect and {{IPA|[j]}} in the Central and Southern dialect) and ''r'' ({{IPA|[z]}} in the Northern dialect and {{IPA|[r]}} in the Central and Southern dialects). Thus, the Central and the Southern dialects can be said to have retained a pronunciation closer to Vietnamese orthography and resemble how Middle Vietnamese sounded, in contrast to the modern Northern (Hanoi) dialect, which has since undergone pronunciation shifts. 
<!-- Do not delete this paragraph, as it effectively explains basic differences in evolution of phonology (via English phonetics) without complicated tables and graphs. Also, accents may change over time as some pronunciations get casted into antiquity in favour of more agreeable Vietnamese speech.-->

===Vocabulary===
{| class="wikitable" style="text-align: center;"
|+ {{Anchor|Examples of regional variation in grammatical words}}Regional variation in vocabulary<ref>Table data from {{harvtxt|Hoàng|1989}}.</ref>
! Northern !! Central !! Southern !! English gloss
|-
| ''vâng'' || ''dạ'' || ''dạ'' || "yes"
|-
| ''này'' || ''ni'', ''nì'' || ''nè'' || "this"
|-
| ''thế này'', ''như này'' || ''như ri'', ''a ri'' || ''như vầy'' || "thus, this way"
|-
| ''đấy'' || ''nớ'', ''tê'' || ''đó'' || "that"
|-
| ''thế'', ''thế ấy'', ''thế đấy'' || ''rứa'', ''rứa tê'' || ''vậy'', ''vậy đó'' || "thus, so, that way"
|-
| ''kia'', ''kìa'' || ''tê'', ''tề'' || ''đó'' || "that yonder"
|-
| ''đâu'' || ''mô'' || ''đâu'' || "where"
|-
| ''nào'' || ''mồ'' || ''nào'' || "which"
|-
| ''tại sao'' || ''răng'' || ''tại sao'' || "why"
|-
| ''thế nào'', ''như nào'' || ''răng'', ''mần răng'' || ''làm sao'' || "how" 
|-
| ''tôi, tui'' || ''tui'' || ''tui'' || "I, me (polite)"
|-
| ''tao'' || ''tau'' || ''tao'' || "I, me (informal, familiar)"
|-
| ''chúng tao'', ''bọn tao'', ''chúng tôi'', ''bọn tôi'' || ''choa'', ''bọn choa'' || ''tụi tao'', ''tụi tui'', ''bọn tui'' || "we, us (but not you, colloquial, familiar)"
|-
| ''mày'' || ''mi'' || ''mày'' || "you (informal, familiar)"
|-
| ''chúng mày'', ''bọn mày'' || ''bây'', ''bọn bây'' || ''tụi mầy'', ''tụi bây'', ''bọn mày'' || "you guys (informal, familiar)"
|-
|''nó''
|''hắn'', ''hấn''
|''nó''
|"he/she/it (informal, familiar)"
|-
| ''chúng nó'', ''bọn nó'' || ''bọn nớ'' || ''tụi nó'' || "they/them (informal, familiar)"
|-
| ''ông ấy'' || ''ông nớ'' || ''ổng'' || "he/him, that gentleman, sir"
|-
| ''bà ấy'' || ''bà nớ'' || ''bả''|| "she/her, that lady, madam"
|-
| ''anh ấy'' || ''anh nớ'' || ''ảnh'' || "he/him, that young man (of equal status)"
|-
| ''ruộng'' || ''nương'' || ''ruộng'', ''rẫy'' || "field"
|-
| ''bát'' || ''đọi'' || ''chén'', ''tô'' || "rice bowl" 
|-
| ''muôi'', ''môi'' || ''môi'' || ''vá'' || "ladle" 
|-
| ''đầu'' || ''trốc'' || ''đầu'' || "head" 
|-
| ''ô tô'' || ''ô tô'' || ''xe hơi'' ''(ô tô)'' || "car" 
|-
| ''thìa'' || ''thìa'' || ''muỗng'' || "spoon" 
|-
|''bố''
|''bọ''
|''ba''
|"father"
|}
Although regional variations developed over time, most of those words can be used interchangeably and be understood well, albeit with more or less frequency then others or with slightly different but often discernible word choices and pronunciations. Some accents may mix, with words such ''dạ vâng'' combining ''dạ'' and ''vâng,'' being created''.''

===Consonants===
The [[syllable]]-initial ''ch'' and ''tr'' digraphs are pronounced distinctly in the North-Central, Central, and Southern varieties but are merged in Northern varieties, which pronounce them the same way). Many North-Central varieties preserve three distinct pronunciations for ''d'', ''gi'', and ''r'', but the Northern varieties have a three-way merger, and the Central and the Southern varieties have a merger of ''d'' and ''gi'' but keep ''r'' distinct. At the end of syllables, the palatals ''ch'' and ''nh'' have merged with the alveolars ''t'' and ''n'', which, in turn, have also partially merged with velars ''c'' and ''ng'' in the Central and the Southern varieties.

{| class="wikitable" style="text-align: center;"
|+ Regional consonant correspondences{{Anchor|Regional consonant correspondences}}
! Syllable position !! Orthography !! Northern !! North-central !! Central !! Southern
|-
! rowspan=8 | syllable-initial
! ''x''
| rowspan=2 | {{IPA|[s]}}
| colspan=3 | {{IPA|[s]}}
|-
! ''s''
| colspan=2 | {{IPA|[ʂ]}} || {{IPA|[s, ʂ]}}{{efn|name="retroflex"|In southern dialects, ''ch'' and ''tr'' are increasingly being merged as {{IPA|[c]}}. Similarly, ''x'' and ''s'' are increasingly being merged as {{IPA|[s]}}.}}
|-
! ''ch''
| rowspan=2 | {{IPA|[t͡ɕ]}}
| colspan=3 | {{IPA|[c]}}
|-
! ''tr''
| colspan=2 | {{IPA|[ʈ]}} || {{IPA|[c, ʈ]}}{{efn|name="retroflex"}}
|-
! ''r''
| rowspan=3 | {{IPA|[z]}}
| colspan=3 | {{IPA|[r]}}
|-
! ''d''
| {{varies}}
| rowspan=2 colspan=3 | {{IPA|[j]}}
|-
! ''gi''
| {{varies}}
|-
! ''v''
| colspan=3 | {{IPA|[v]}}
| {{IPA|[v, j]}}{{efn|In the southern dialects, ''v'' is increasingly pronounced {{IPA|[v]}} among educated speakers. Less educated speakers use {{IPA|[j]}} more consistently throughout their speech.}}
|-
! rowspan=12 | syllable-final
! ''t''
| colspan=2 | {{IPA|[t]}}
| rowspan=2 colspan=2 | {{IPA|[k]}}
|-
! ''c''
| colspan=2 | {{IPA|[k]}}
|-
! style="line-height: 1em;" | ''t'' <br /><span style="font-weight: normal; font-size: small;">after ''i'', ''ê''</span>
| colspan=2 | {{IPA|[t]}}
| rowspan=2 colspan=2 | {{IPA|[t]}}
|-
! ''ch''
| colspan=2 | {{IPA|[k̟]}}
|-
! style="line-height: 1em;" | ''t'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô''</span>
| colspan=2 | {{IPA|[t]}}
| rowspan=2 colspan=2 | {{IPA|[kp]}}
|-
! style="line-height: 1em;" | ''c'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô'', ''o''</span>
| colspan=2 | {{IPA|[kp]}}
|-
! ''n''
| colspan=2 | {{IPA|[n]}}
| rowspan=2 colspan=2 | {{IPA|[ŋ]}}
|-
! ''ng''
| colspan=2 | {{IPA|[ŋ]}}
|-
! style="line-height: 1em;" | ''n'' <br /><span style="font-weight: normal; font-size: small;">after ''i'', ''ê''</span>
| colspan=2 | {{IPA|[n]}}
| rowspan=2 colspan=2 | {{IPA|[n]}}
|-
! ''nh''
| colspan=2 | {{IPA|[ŋ̟]}}
|-
! style="line-height: 1em;" | ''n'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô''</span>
| colspan=2 | {{IPA|[n]}}
| rowspan=2 colspan=2 | {{IPA|[ŋm]}}
|-
! style="line-height: 1em;" | ''ng'' <br /><span style="font-weight: normal; font-size: small;">after ''u'', ''ô'', ''o''</span>
| colspan=2 | {{IPA|[ŋm]}}
|}

In addition to the regional variation described above, there is a merger of ''l'' and ''n'' in certain rural varieties in the North:{{sfnp|Kirby|2011|p=382}}

{| class="wikitable" style="text-align: center;"
|+ ''l'', ''n'' variation
! Orthography
! "Mainstream" varieties
! Rural varieties
|-
! ''n''
| {{IPA|[n]}}
| rowspan="2" | {{IPA|[l]}}
|-
! ''l''
| {{IPA|[l]}}
|}

Variation between ''l'' and ''n'' can be found even in mainstream Vietnamese in certain words. For example, the numeral "five" appears as ''năm'' by itself and in compound numerals like ''năm mươi'' "fifty", but it appears as {{lang|vi|lăm}} in {{lang|vi|mười lăm}} "fifteen" (see [[Vietnamese grammar#Cardinal]]). In some northern varieties, the numeral appears with an initial ''nh'' instead of ''l'': {{lang|vi|hai mươi nhăm}} "twenty-five", instead of the mainstream {{lang|vi|hai mươi lăm}}.{{efn|Gregerson (1981) notes that the variation was present in de Rhodes's time in some initial consonant clusters: ''mlẽ'' ~ ''mnhẽ'' "reason" (cf. modern Vietnamese ''lẽ'' "reason").}}

There is also a merger of ''r'' and ''g'' in certain rural varieties in the South:

{| class="wikitable" style="text-align: center;"
|+ ''r'', ''g'' variation
! Orthography
! "Mainstream" varieties
! Rural varieties
|-
! ''r''
| {{IPA|[r]}}
| rowspan="2" | {{IPA|[ɣ]}}
|-
! ''g''
| {{IPA|[ɣ]}}
|}

The consonant clusters that were originally present in Middle Vietnamese (in the 17th century) have been lost in almost all modern Vietnamese varieties although they have been retained in other closely related [[Vietic languages]]. However, some speech communities have preserved some of these archaic clusters: "sky" is {{lang|vi|blời}} with a cluster in Hảo Nho ([[Yên Mô District|Yên Mô]], [[Ninh Bình Province]]) but ''trời'' in Southern Vietnamese and {{lang|vi|giời}} in Hanoi Vietnamese (initial single consonants {{IPA|/ʈ/, /z/}}, respectively).

===Tones===
There are six tones in Vietnamese, with phonetic differences between dialects, mostly in the pitch contour and [[phonation]] type.

{| class="wikitable" style="text-align: center;"
|+ Regional tone correspondences{{Anchor|Regional tone correspondences}}
! rowspan="2" | Tone
! rowspan="2" | Northern
! colspan="3" | North-central
! rowspan="2" | Central
! rowspan="2" | Southern
|- style="font-size: small; line-height: 1.1em;"
! ''&nbsp;Vinh&nbsp;'' !! ''Thanh<br />Chương'' !! ''Hà Tĩnh''
|-
! style="text-align: left;" | ''ngang''
| {{IPA|˧ 33}} || {{IPA|˧˥ 35}} || {{IPA|˧˥ 35}} ||{{IPA|˧˥ 35, ˧˥˧ 353}} ||{{IPA|˧˥ 35}} ||{{IPA|˧ 33}}
|-
! style="text-align: left;" | ''huyền''
|{{IPA|˨˩̤ 21̤}} ||{{IPA|˧ 33}} ||{{IPA|˧ 33}} ||{{IPA|˧ 33}} ||{{IPA|˧ 33}} ||{{IPA|˨˩ 21}}
|-
! style="text-align: left;" | ''sắc''
|{{IPA|˧˥ 35}} ||{{IPA|˩ 11}} ||{{IPA|˩ 11, ˩˧̰ 13̰}} || {{IPA|˩˧̰ 13̰}} || {{IPA|˩˧̰ 13̰}} || {{IPA|˧˥ 35}}
|-
! style="text-align: left;" | ''hỏi''
| {{IPA|˧˩˧̰ 31̰3}} ||{{IPA|˧˩ 31}}
| rowspan="2" | {{IPA|˧˩ 31}}
| {{IPA|˧˩̰ʔ 31̰ʔ}}
| rowspan="2" |{{IPA|˧˩˨ 312}}
| rowspan="2" |{{IPA|˨˩˦ 214}}
|-
! style="text-align: left;" | ''ngã''
|{{IPA|˧ʔ˥ 3ʔ5}} ||{{IPA|˩˧̰ 13̰}}
| rowspan="2" |{{IPA|˨̰ 22̰}}
|-
! style="text-align: left;" | ''nặng''
| {{IPA|˨˩̰ʔ 21̰ʔ}} ||{{IPA|˨ 22}} ||{{IPA|˨̰ 22̰}} || {{IPA|˨̰ 22̰}} ||{{IPA|˨˩˨ 212}}
|}

The table above shows the pitch contour of each tone using [[Tone (linguistics)#Asia|Chao tone number notation]] in which 1 represents the lowest pitch, and 5 the highest; [[glottalization]] ([[creaky voice|creaky]], [[stiff voice|stiff]], [[harsh voice|harsh]]) is indicated with the {{angbr IPA|◌̰}} symbol; [[murmured voice]] with {{angbr IPA|◌̤}}; [[glottal stop]] with {{angbr IPA|ʔ}}; sub-dialectal variants are separated with commas. (See also the [[#Tones|tone section]] below.)

==Word play==
A basic form of [[word play]] in Vietnamese involves disyllabic words in which the last syllable forms the first syllable of the next word in the chain. This game involves two members versing each other until the opponent is unable to think of another word. For instance: 
{| class="wikitable"
|-
| Hậu trường (backstage) || → || Trường học (School) 
|→|| Học tập (Study)
|→
|Tập trung (Concentrate)
|→
|-
| Trung tâm (Centre) || → || Tâm lí (Mentality) 
|→|| Lí do (Reason)
|→
|Etc., until someone cannot form the next word or, if the word play is used as a game, gives up.
|
|}

Another [[language game]] known as ''nói lái'' is used by Vietnamese speakers.{{sfn|Nguyễn|1997|pp=28–29}} ''Nói lái'' involves switching, adding or removing the tones in a pair of words and may also involve switching the order of words or the first consonant and the [[Syllable rime|rime]] of each word. Some examples:

:{| class="wikitable"
! Original phrase !! !! Phrase after ''nói lái'' transformation !! Structural change
|-
| ''đái dầm'' "(child) pee" || → || ''dấm đài'' (literal translation "vinegar stage") || word order and tone switch
|-
| ''chửa hoang'' "pregnancy out of wedlock" || → || ''hoảng chưa'' "scared yet?" || word order and tone switch
|-
| ''bầy tôi'' "all the king's subjects" || → || ''bồi tây'' "west waiter" || initial consonant, rime, and tone switch
|-
| ''bí mật'' "secrets" || → || ''bật mí'' "reveal" || initial consonant and rime switch
|-
| ''Tây Ban Nha'' "Spain (España)" || → || ''Tây Bán Nhà'' (literal translation "West Sell House", mainly used to mock [[Spain men's national football team|Spain national football team]]<ref>{{Citation |title=Nhạc chế World Cup 2018 {{!}} TÂY BÁN NHÀ {{!}} Ronaldo còn có nhà mà về |url=https://www.youtube.com/watch?v=bTIFecbWc7c |access-date=2023-08-30 |language=en}}</ref>) || initial consonant, rime, and tone switch
|-
| ''Bồ Đào Nha'' "Portugal" || → || ''Nhà Đào Bô'' (literal translation "House Dig Bucket", mainly used to mock [[Portugal national football team]]) || word order and tone switch
|}

The resulting transformed phrase often has a different meaning but sometimes may just be a nonsensical word pair. ''Nói lái'' can be used to obscure the original meaning and thus soften the discussion of a socially sensitive issue, as with ''dấm đài'' and ''hoảng chưa'' (above), or when implied (and not overtly spoken), to deliver a hidden subtextual message, as with ''bồi tây''.{{efn|{{harvnb|Nguyễn|1997|p=29}} gives the following context: "... a collaborator under the French administration was presented with a congratulatory panel featuring the two Chinese characters ''quần thần''. This Sino-Vietnamese expression could be defined as ''bầy tôi'' meaning 'all the king's subjects'. But those two syllables, when undergoing commutation of rhyme and tone, would generate ''bồi tây'' meaning 'servant in a French household'."}} Naturally, ''nói lái'' can be used for a humorous effect.<ref>[http://www.users.bigpond.com/doanviettrung/noilai.html www.users.bigpond.com/doanviettrung/noilai.html] {{Webarchive|url=https://web.archive.org/web/20080222075952/http://www.users.bigpond.com/doanviettrung/noilai.html |date=2008-02-22 }}, Language Log's [http://itre.cis.upenn.edu/~myl/languagelog/archives/001788.html itre.cis.upenn.edu/~myl/languagelog/archives/001788.html], and [http://tphcm.blogspot.com/2005/01/ni-li.html tphcm.blogspot.com/2005/01/ni-li.html] for more examples.</ref>

Another word game somewhat reminiscent of [[pig latin]] is played by children. Here a nonsense syllable (chosen by the child) is prefixed onto a target word's syllables, then their initial consonants and rimes are switched with the tone of the original word remaining on the new switched rime.

:{| class="wikitable"
! Nonsense syllable !! Target word !! !! Intermediate form with prefixed syllable !! !! Resulting "secret" word
|-
| ''la'' || ''phở'' "beef or chicken noodle soup" || → || ''la phở'' || → || ''lơ phả''
|-
| ''la'' || ''ăn'' "to eat" || → || ''la ăn'' || → || ''lăn a''
|-
| ''la'' || ''hoàn cảnh'' "situation" || → || ''la hoàn la cảnh'' || → || ''loan hà lanh cả''
|-
| ''chim'' || ''hoàn cảnh'' "situation" || → || ''chim hoàn chim cảnh'' || → || ''choan hìm chanh kỉm''
|}

This language game is often used as a "secret" or "coded" language useful for obscuring messages from adult comprehension.

==See also==
{{Portal|Vietnam|Language}}
* [[Vietnamese Wikipedia]]
*[[Vietnamese calligraphy]]
*[[Vietnamese pronouns]]
* [[Vietnamese studies]]

==Notes==
{{notelist}}

==References==
{{Reflist}}

==Bibliography==

===General===
* Dương, Quảng-Hàm. (1941). ''Việt-nam văn-học sử-yếu'' [Outline history of Vietnamese literature]. Saigon: Bộ Quốc gia Giáo dục.
* {{cite journal | surname = Emeneau | given = M. B. | author-link = Murray Barnson Emeneau | year = 1947 | title = Homonyms and puns in Annamese | journal = Language | volume = 23 | issue = 3| pages = 239–244 | doi = 10.2307/409878 | jstor = 409878 }}
* {{cite book | surname = Emeneau | given = M. B. | author-mask = 3 | year = 1951 | title = Studies in Vietnamese (Annamese) grammar | series = University of California publications in linguistics | volume = 8 | location = Berkeley | publisher = University of California Press }}
* {{cite journal | surname = Hashimoto | given = Mantaro | author-link = Hashimoto Mantaro | title = Current developments in Sino-Vietnamese studies | journal = Journal of Chinese Linguistics | volume = 6 | issue = 1 | pages = 1–26 | year = 1978 | jstor = 23752818 }}
* {{cite book | surname = Marr | given = David G. | title = Vietnamese Tradition on Trial, 1920–1945 | publisher = University of California Press | year = 1984 | isbn = 978-0-520-90744-7 }}
* {{cite book | surname = Nguyễn | given = Đình-Hoà | title = NTC's Vietnamese–English dictionary | edition = updated | location = Lincolnwood, Illinois | publisher = NTC | year = 1995 | isbn = 0-8442-8357-6 }}
* {{cite book | surname = Nguyễn | given = Đình-Hoà | author-mask = 3 | title = Vietnamese: Tiếng Việt không son phấn | location = Amsterdam | publisher = John Benjamins | year = 1997 | isbn = 90-272-3809-X }}
* {{cite book|last=Nguyen|first=Dinh Tham|title=Studies on Vietnamese Language and Literature: A Preliminary Bibliography|year=2018|publisher=Cornell University Press|isbn=978-1-501-71882-3}}
* {{cite book|last=Rhodes|first=Alexandre de|editor1=L. Thanh|editor2=X. V. Hoàng|editor3=Q. C. Đỗ|title=[[Dictionarium Annamiticum Lusitanum et Latinum]]|year=1991|publisher=Khoa học Xã hội|location=Hanoi}}
* {{cite book | surname = Thompson | given = Laurence C. | title = A Vietnamese reference grammar | location = Honolulu | publisher = University of Hawaii Press | year = 1991 | orig-year = 1965 | isbn = 0-8248-1117-8 | url = http://www.sealang.net/archives/mks/THOMPSONLaurenceC.htm }}
* Uỷ ban Khoa học Xã hội Việt Nam. (1983). ''Ngữ-pháp tiếng Việt'' [Vietnamese grammar]. Hanoi: Khoa học Xã hội.

===Sound system===
*{{cite journal | last1 = Brunelle | first1 = Marc | year = 2009 | title = Tone perception in Northern and Southern Vietnamese | journal = Journal of Phonetics | volume = 37 | issue = 1| pages = 79–96 | doi = 10.1016/j.wocn.2008.09.003 }}
*{{cite journal | last1 = Brunelle | first1 = Marc | year = 2009 | title = Northern and Southern Vietnamese Tone Coarticulation: A Comparative Case Study | url = http://www.jseals.org/JSEALS-1.pdf#page=55 | archive-url = https://web.archive.org/web/20181113080707/http://www.jseals.org/JSEALS-1.pdf#page=55 | url-status = dead | archive-date = 2018-11-13 | journal = Journal of Southeast Asian Linguistics | volume = 1 | pages = 49–62 }}
* {{cite journal |title=Vietnamese (Hanoi Vietnamese) |first=James P. |last=Kirby |journal=Journal of the International Phonetic Association |year=2011 |volume=41 |issue=3 |pages=381–392 |doi=10.1017/S0025100311000181 |s2cid=144227569 |url=http://www.lel.ed.ac.uk/~jkirby/docs/kirby2011vietnamese.pdf }}
* {{cite journal | last1 = Michaud | first1 = Alexis | year = 2004 | title = Final consonants and glottalization: New perspectives from Hanoi Vietnamese | url = http://hal.archives-ouvertes.fr/hal-00130119/en/ | journal = Phonetica | volume = 61 | issue = 2–3| pages = 119–146 | doi = 10.1159/000082560 | pmid = 15662108 | s2cid = 462578 }}
* {{cite journal | last1 = Nguyễn | first1 = Văn Lợi | last2 = Edmondson | first2 = Jerold A | year = 1998 | title = Tones and voice quality in modern northern Vietnamese: Instrumental case studies | url = http://www.sealang.net/archives/mks/NGUYNVnLoi.htm | journal = [[Mon-Khmer Studies]] | volume = 28 | pages = 1–18 }}
* {{cite journal | last1 = Thompson | first1 = Laurence E | year = 1959 | title = Saigon phonemics | journal = Language | volume = 35 | issue = 3| pages = 454–476 | doi = 10.2307/411232 | jstor = 411232 }}

===Language variation===
* Alves, Mark J. 2007. [http://sealang.net/sala/archives/pdf8/alves2002look.pdf "A Look At North-Central Vietnamese"] In ''SEALS XII Papers from the 12th Annual Meeting of the Southeast Asian Linguistics Society 2002'', edited by Ratree Wayland et al. Canberra, Australia, 1–7. Pacific Linguistics, Research School of Pacific and Asian Studies, The Australian National University
* Alves, Mark J.; & Nguyễn, Duy Hương. (2007). [https://web.archive.org/web/20080216015159/http://pacling.anu.edu.au/catalogue/SEALSVIII_final.pdf "Notes on Thanh-Chương Vietnamese in Nghệ-An province"]. In M. Alves, M. Sidwell, & D. Gil (Eds.), ''SEALS VIII: Papers from the 8th annual meeting of the Southeast Asian Linguistics Society 1998'' (pp.&nbsp;1–9). Canberra: Pacific Linguistics, The Australian National University, Research School of Pacific and Asian Studies
* {{cite book | surname = Hoàng | given = Thị Châu | year = 1989 | title = Tiếng Việt trên các miền đất nước: Phương ngữ học | trans-title = Vietnamese in different areas of the country: Dialectology | location = Hanoi | publisher = Khoa học xã hội }}
* Honda, Koichi. (2006). [https://assta.org/proceedings/sst/2006/sst2006-119.pdf "F0 and phonation types in Nghe Tinh Vietnamese tones"]. In P. Warren & C. I. Watson (Eds.), ''Proceedings of the 11th Australasian International Conference on Speech Science and Technology'' (pp.&nbsp;454–459). Auckland, New Zealand: University of Auckland.
* Michaud, Alexis; Ferlus, Michel; & Nguyễn, Minh-Châu. (2015). [https://www.researchgate.net/publication/280959628_Strata_of_standardization_The_Phong_Nha_dialect_of_Vietnamese_Quang_Binh_Province_in_historical_perspective "Strata of standardization: the Phong Nha dialect of Vietnamese (Quảng Bình Province)] in historical perspective". ''Linguistics of the Tibeto-Burman Area'', Dept. of Linguistics, University of California, 2015, 38 (1), pp.&nbsp;124–162.
* Pham, Andrea Hoa. (2005). [https://web.archive.org/web/20080216015159/http://r1.chass.utoronto.ca/twpl/pdfs/twpl24/Pham_TWPL24.pdf "Vietnamese tonal system in Nghi Loc: A preliminary report"]. In C. Frigeni, M. Hirayama, & S. Mackenzie (Eds.), ''Toronto working papers in linguistics: Special issue on similarity in phonology'' (Vol. 24, pp.&nbsp;183–459). Auckland, New Zealand: University of Auckland.
* Vũ, Thanh Phương. (1982). "Phonetic properties of Vietnamese tones across dialects". In D. Bradley (Ed.), ''Papers in Southeast Asian linguistics: Tonation'' (Vol. 8, pp.&nbsp;55–75). Sydney: Pacific Linguistics, The Australian National University.
* Vương, Hữu Lễ. (1981). "Vài nhận xét về đặc diểm của vần trong thổ âm Quảng Nam ở Hội An" [Some notes on special qualities of the rhyme in local Quảng Nam speech in Hội An]. In ''Một Số Vấn Ðề Ngôn Ngữ Học Việt Nam'' [Some linguistics issues in Vietnam] (pp.&nbsp;311–320). Hà Nội: Nhà Xuất Bản Ðại Học và Trung Học Chuyên Nghiệp.

===Pragmatics===
* Luong, Hy Van. (1987). "Plural markers and personal pronouns in Vietnamese person reference: An analysis of pragmatic ambiguity and negative models". ''Anthropological Linguistics'', '''29'''(1), 49–70. {{JSTOR|30028089}}
* {{cite journal | last1 = Sophana | first1 = Srichampa | year = 2004 | title = Politeness strategies in Hanoi Vietnamese speech | url = http://www.sealang.net/archives/mks/SOPHANASrichampa.htm | journal = [[Mon-Khmer Studies]] | volume = 34 | pages = 137–157 }}
* {{cite journal | last1 = Sophana | first1 = Srichampa | year = 2005 | title = Comparison of greetings in the Vietnamese dialects of Ha Noi and Ho Chi Minh City | url = http://www.sealang.net/archives/mks/SOPHANASrichampa.htm | journal = [[Mon-Khmer Studies]] | volume = 35 | pages = 83–99 }}

===Historical and comparative===
* {{cite book | given = Mark J. | surname = Alves | chapter = What's So Chinese About Vietnamese? | pages = 221–242 | chapter-url = http://sealang.net/sala/archives/pdf8/alves2001what.pdf | title = Papers from the Ninth Annual Meeting of the Southeast Asian Linguistics Society | editor-given = Graham W. | editor-surname = Thurgood | publisher = Arizona State University, Program for Southeast Asian Studies | year = 2001 | isbn = 978-1-881044-27-7 }}
* {{cite journal | surname = Alves | given = Mark | title = Historical Ethnolinguistic Notes on Proto-Austroasiatic and Proto-Vietic Vocabulary in Vietnamese | journal = Journal of the Southeast Asian Linguistics Society | volume = 13 | issue = 2 | year = 2020 | pages = xiii–xlv | hdl = 10524/52472 | hdl-access = free }}
* {{cite book | surname = Alves | given = Mark | chapter = Linguistic influence of Chinese in Southeast Asia | pages = 649–671 | doi = 10.1515/9783110558142-027 | title=The Languages and Linguistics of Mainland Southeast Asia: A Comprehensive Guide | editor-last=Sidwell | editor-first=Paul | editor-last2=Jenny | editor-first2=Mathias | location=Berlin | publisher=De Gruyter Mouton | year=2021 | isbn=978-3-11-055606-3 }}
* {{citation| surname1 =Chamberlain | given1 = James | chapter =Vanishing Nomads: Languages and Peoples of Nakai, Laos, and Adjacent Areas| pages = 1589–1606| title = Handbook of the Changing World Language Map| editor-given1 = Stanley | editor-surname1 = Brunn| editor-given2 = Roland | editor-surname2 = Kehrein | location = Vientiane | publisher = Springer International Publishing| year = 2019|isbn=978-3-03002-437-6}}
* Cooke, Joseph R. (1968). ''Pronominal reference in Thai, Burmese, and Vietnamese''. University of California publications in linguistics (No. 52). Berkeley: University of California Press.
* {{cite journal
|last=Ferlus
|first=Michel
|title=Histoire abrégée de l'évolution des consonnes initiales du Vietnamien et du Sino-Vietnamien
|url=https://halshs.archives-ouvertes.fr/halshs-00923038
|year=1992
|journal=[[Mon-Khmer Studies]]
|volume=20
|pages=111–125}}
* {{cite journal|last1=Ferlus|first1=Michel|title=A Layer of Dongsonian Vocabulary in Vietnamese|journal=Journal of the Southeast Asian Linguistics Society|date=2009|volume=1|pages=95–108|url=https://halshs.archives-ouvertes.fr/halshs-00932218v3 }} 
* {{cite journal | last1 = Gong | first1 = Xun | year = 2019 | title = Chinese loans in Old Vietnamese with a sesquisyllabic phonology. | journal = Journal of Language Relationship | volume = 17 | issue = 1–2| pages = 55–72 | doi = 10.31826/jlr-2019-171-209 | doi-access = free | s2cid = 212689052 }}
* Gregerson, Kenneth J. (1969). "A study of Middle Vietnamese phonology". ''Bulletin de la Société des Études Indochinoises'', '''44''', 135–193. (Reprinted in 1981).
* {{cite journal | title = Études sur la phonétique historique de la langue annamite. Les initiales | given = Henri | surname = Maspero | journal = Bulletin de l'École française d'Extrême-Orient | year = 1912 | volume = 12 | number = 1 | pages = 1–124 | doi = 10.3406/befeo.1912.2713 | doi-access = free }}
* {{cite journal | last1 = Nguyễn | first1 = Đình-Hoà | year = 1986 | title = Alexandre de Rhodes' dictionary | journal = Papers in Linguistics | volume = 19 | pages = 1–18 | doi = 10.1080/08351818609389247 }}
* {{cite book
| surname = Nguyễn | given = Đình-Hoà | chapter = Vietnamese | pages = 677–692
| title = The World's Major Languages | editor-given = Bernard | editor-surname = Comrie
| publisher = Routledge | edition = 2nd | year = 2009 | isbn = 978-0-415-35339-7
}}
* {{citation
  | title = Past human migrations in East Asia: matching archaeology, linguistics and genetics
  | editor-first1= Alicia | editor-last1= Sanchez-Mazas
  | editor-first2= Roger | editor-last2= Blench
  | editor-first3= Malcolm D. | editor-last3= Ross
  | editor-first4= Peiros | editor-last4= Ilia
  | editor-first5= Marie | editor-last5= Lin
  | publisher = Routledge
  | given1 = Laurent | surname1 = Sagart
  | chapter = The expansion of Setaria farmers in East Asia
  |chapter-url=https://www.academia.edu/3077307
  | year = 2008
  | pages = 133–157
  | isbn = 978-0-415-39923-4
  }}
* {{cite journal |surname1=Sidwell |given1=Paul |author-link1=Paul Sidwell |surname2=Alves |given2=Mark |date=2021 |title=The Vietic languages: a phylogenetic analysis |url=https://jolr.ru/index.php?article=306 |journal=[[Journal of Language Relationship]] |volume=19 |issue=3–4 |pages=166–194}}
* {{cite journal | surname = Shimizu | given = Maasaki | year = 2015 | title = A Reconstruction of Ancient Vietnamese Initials Using Chữ Nôm Materials | journal = NINJAL Research Papers | volume = 9 | issue = 1–2 | pages = 135–158 | doi = 10.15084/00000465 | doi-access = free }}
* {{cite book | surname = Shorto | given = Harry L. | editor1-surname = Sidwell | editor1-given = Paul | editor2-surname = Cooper | editor2-given = Doug | editor3-surname = Bauer | editor3-given = Christian | title = A Mon–Khmer comparative dictionary | location = Canberra | publisher = Pacific Linguistics, Australian National University | year = 2006 | isbn = 0-85883-570-3 | url = https://openresearch-repository.anu.edu.au/items/0d39362c-3ffa-4815-86bf-155af4393de2 }}
* {{cite journal | last1 = Thompson | first1 = Laurence E | year = 1967 | title = The history of Vietnamese final palatals | journal = Language | volume = 43 | issue = 1| pages = 362–371 | doi = 10.2307/411402 | jstor = 411402}}
* {{cite book |last=Phan |first=John D. |title=Lost Tongues of the Red River: Annamese Middle Chinese & the Origins of the Vietnamese Language |date=2025 |publisher=Harvard University Press |url=https://www.hup.harvard.edu/books/9780674301696 |isbn=9780674301696 }}

===Orthography===
* {{cite book | surname = DeFrancis | given = John | author-link = John DeFrancis | title = Colonialism and language policy in Viet Nam | publisher = Mouton | year = 1977 | isbn = 978-90-279-7643-7 }}
*{{Cite journal | last1 = Haudricourt | first1 = André-Georges | year = 1949 | title = Origine des particularités de l'alphabet vietnamien | journal = Dân Việt-Nam | volume = 3 | pages = 61–68 }}
** English translation: {{Cite journal | title = The origin of the peculiarities of the Vietnamese alphabet | first1 = Alexis | last1 = Michaud | first2 = André-Georges | last2 = Haudricourt | journal = [[Mon-Khmer Studies]] | volume = 39 | year = 2010 | pages = 89–104 | url =https://www.academia.edu/2571111 }}
* Nguyễn, Đình-Hoà. (1955). ''Quốc-ngữ: The modern writing system in Vietnam''. Washington, DC: Author.
* {{cite journal | last1 = Nguyễn | first1 = Đình-Hoà | year = 1990 | title = Graphemic borrowing from Chinese: The case of ''chữ nôm'', Vietnam's demotic script | journal = Bulletin of the Institute of History and Philology, Academia Sinica | volume = 61 | pages = 383–432 }}
* Nguyễn, Đình-Hoà. (1996). Vietnamese. In P. T. Daniels, & W. Bright (Eds.), ''The world's writing systems'', (pp.&nbsp;691–699). New York: Oxford University Press. {{ISBN|978-0-19-507993-7}}.

===Pedagogical===
* Nguyen, Bich Thuan. (1997). ''Contemporary Vietnamese: An intermediate text''. Southeast Asian language series. Northern Illinois University, Center for Southeast Asian Studies.
* Healy, Dana. (2004). ''Teach Yourself Vietnamese''. Teach Yourself. Chicago: McGraw-Hill. ISBN
* Hoang, Thinh; Nguyen, Xuan Thu; Trinh, Quynh-Tram; (2000). ''Vietnamese phrasebook'', (3rd ed.). Hawthorn, Vic.: Lonely Planet. ISBN
* Moore, John. (1994). ''Colloquial Vietnamese: A complete language course''. London: Routledge.
* Nguyễn, Đình-Hoà. (1967). ''Read Vietnamese: A graded course in written Vietnamese''. Rutland, Vermont: C.E. Tuttle.
* Lâm, Lý-duc; Emeneau, M. B.; von den Steinen, Diether. (1944). ''An Annamese reader''. Berkeley: University of California, Berkeley.
* Nguyễn, Đăng Liêm. (1970). ''Vietnamese pronunciation''. PALI language texts: Southeast Asia. Honolulu: University of Hawaii Press.

== External links ==
{{InterWiki|code=vi}}
{{Wikibooks|Vietnamese}}
{{Commons category|Vietnamese language}}
; Online lessons
* [https://www.seasite.niu.edu/vietnamese/VNLanguage/SupportNS/tableofcontent.htm Online Vietnamese lessons] {{Webarchive|url=https://web.archive.org/web/20091010223840/https://www.seasite.niu.edu/vietnamese/VNLanguage/SupportNS/tableofcontent.htm |date=2009-10-10 }} from [[Northern Illinois University]]

; Vocabulary
{{wikivoyage|Vietnamese phrasebook|Vietnamese|a phrasebook}}
* [https://wold.clld.org/vocabulary/24 Vietnamese Vocabulary List] (from the World Loanword Database)
* [https://en.wiktionary.org/wiki/Appendix:Vietnamese_Swadesh_list Swadesh list of Vietnamese basic vocabulary words] (from Wiktionary's [https://en.wiktionary.org/wiki/Appendix:Swadesh_lists Swadesh-list appendix])

; Language tools
* [https://just.nicepeople.free.fr/kbd/ The Vietnamese keyboard] its layout is compared with US, UK, Canada, France, and Germany's keyboards.
* [https://web.archive.org/web/20181013093753/https://www.informatik.uni-leipzig.de/~duc/Dict/index.html The Free Vietnamese Dictionary Project]
'''Research projects and data resources'''
* [https://projekt.ht.lu.se/rwaai rwaai | Projects] RWAAI (Repository and Workspace for Austroasiatic Intangible Heritage)
* [[hdl:10050/00-0000-0000-0003-93ED-5@view|Vietnamese in RWAAI Digital Archive]]

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