Editing Proto-Germanic language (section)

===Phonological stages from Proto-Indo-European to end of Proto-Germanic===
{{See also|Germanic parent language}}
The following changes are known or presumed to have occurred in the history of Proto-Germanic in the wider sense from the end of Proto-Indo-European up to the point that Proto-Germanic began to break into mutually unintelligible dialects. The changes are listed roughly in chronological order, with changes that operate on the outcome of earlier ones appearing later in the list. The stages distinguished and the changes associated with each stage rely heavily on Ringe, who in turn summarizes standard concepts and terminology.<ref>{{Cite book |last=Ringe |first=Don |title=From Proto-Indo-European to Proto-Germanic (2nd edn) |date=2006 |chapter=3. The development of Proto-Germanic}}</ref>

====Pre-Proto-Germanic (Pre-PGmc)====
This stage began with the separation of a distinct speech, perhaps while it was still forming part of the Proto-Indo-European dialect continuum. It contained many innovations that were shared with other Indo-European branches to various degrees, probably through areal contacts, and mutual intelligibility with other dialects would have remained for some time. It was nevertheless on its own path, whether dialect or language.

{| class="wikitable"
|-
|'''Allophonic colouring of {{PIE|/e/}}''' adjacent to laryngeal consonants:
* {{PIE|/h₂e/}} > {{PIE|/h₂a/}} — {{nowrap|''{{PIE|*h₂énti}}'' 'in front' > ''{{PIE|*h₂ánti}}'' > {{lang|gem-x-proto|*andi}} 'in addition'}}
* {{PIE|/eh₂/}} > {{PIE|/ah₂/}} — {{nowrap|''{{PIE|*meh₂tḗr}}'' 'mother' > ''{{PIE|*mah₂tḗr}}'' > {{lang|gem-x-proto|*mōdēr}}}}
* {{PIE|/h₃e/}} > {{PIE|/h₃o/}} — ''{{PIE|*h₃érō}}'' 'eagle' > ''{{PIE|*h₃órō}}'' > {{lang|gem-x-proto|*arô}}
* {{PIE|/eh₃/}} > {{PIE|/oh₃/}} — ''{{PIE|*bʰléh₃mō}}'' 'flower' > ''{{PIE|*bʰlóh₃mō}}'' > {{lang|gem-x-proto|*blōmô}}
|-
|'''Merging of PIE "palatovelar" and "velar" plosives''' ("centumization"):
* {{PIE|/ḱ/}} > {{PIE|/k/}} — ''{{PIE|*ḱm̥tóm}}'' 'hundred' > ''{{PIE|*km̥tóm}}'' > {{lang|gem-x-proto|*hundą}}
* {{PIE|/ǵ/}} > {{PIE|/g/}} — ''{{PIE|*wérǵom}}'' 'work' > ''{{PIE|*wérgom}}'' > {{lang|gem-x-proto|*werką}}
* {{PIE|/ǵʰ/}} > {{PIE|/gʰ/}} — ''{{PIE|*ǵʰh₁yéti}}'' 'to go, walk' > ''{{PIE|*gʰh₁yéti}}'' > {{lang|gem-x-proto|*gaiþi}}
* The actual pronunciation of the "palatovelar" and "velar" series is not reconstructible; it may be that the "palatovelars" were actually plain velars, and the "velars" were pronounced even farther back (post-velar or uvular) so it may be more accurate to say that, for example, {{PIE|/k/}} > {{PIE|/ḱ/}}.{{sfn|Ringe|2006|p=87}} Some also claim that the two series may not even have been distinct in PIE. See [[centum and satem languages]].
|-
|'''[[Epenthesis]] of {{PIE|/u/}}''' before the [[syllabic consonant|syllabic]] [[sonorants]]:
* {{PIE|/m̥/}} > {{PIE|/um/}} — ''{{PIE|*ḱm̥tóm}}'' 'hundred' > ''{{PIE|*kumtóm}}'' > {{lang|gem-x-proto|*hundą}}
* {{PIE|/n̥/}} > {{PIE|/un/}} — ''{{PIE|*n̥tér}}'' 'inside' > ''{{PIE|*untér}}'' > {{lang|gem-x-proto|*under}} 'among'
* {{PIE|/l̥/}} > {{PIE|/ul/}} — ''{{PIE|*wĺ̥kʷos}}'' 'wolf' > ''{{PIE|*wúlkʷos}}'' > {{lang|gem-x-proto|*wulfaz}}
* {{PIE|/r̥/}} > {{PIE|/ur/}} — ''{{PIE|*wŕ̥mis}}'' 'worm' > ''{{PIE|*wúrmis}}'' > {{lang|gem-x-proto|*wurmiz}}
|-
|'''An epenthetic {{PIE|/s/}}''' was inserted already in PIE after dental consonants when they were followed by a suffix beginning with a dental.
* This sequence now becomes {{PIE|/TsT/}} > {{PIE|/ts/}} > {{PIE|/ss/}} — {{nowrap|''{{PIE|*wid-tós}}'' 'known' (pronounced ''{{PIE|*widstos}}'') > ''{{PIE|*witstós}}'' > ''{{PIE|*wissós}}'' > {{lang|gem-x-proto|*wissaz}} 'certain'}}
|-
|'''[[Geminate]] consonants are shortened''' after a consonant or a long vowel — {{nowrap|''{{PIE|*káyd-tis}}'' 'act of calling' (pronounced ''{{PIE|*káydstis}}'') > ''{{PIE|*káyssis}}'' > ''{{PIE|*káysis}}'' > {{lang|gem-x-proto|*haisiz}} 'command'}}
|-
|'''Word-final long vowels are lengthened''' to "overlong" vowels — ''{{PIE|*séh₁mō}}'' 'seeds' > ''{{PIE|*séh₁mô}}'' > {{lang|gem-x-proto|*sēmô}}
|-
|'''Loss [[laryngeal theory|of laryngeals]]''', phonemicising the [[allophone]]s of {{PIE|/e/}}:
* Word-initial [[Glottal consonants|laryngeals]] are lost before a consonant — {{nowrap|''{{PIE|*h₁dóntm̥}}'' 'tooth, acc.' > ''{{PIE|*dóntum}}'' > {{lang|gem-x-proto|*tanþų}}}}
* Laryngeals are lost before vowels — ''{{PIE|*h₁ésti}}'' 'is' > ''{{PIE|*ésti}}'' > {{lang|gem-x-proto|*isti}}
* Laryngeals are lost after vowels but lengthen the preceding vowel: {{PIE|/VH/}} > {{PIE|/Vː/}} — {{nowrap|''{{PIE|*séh₁mō}}''}} 'seeds' > {{lang|gem-x-proto|*sēmô}}
** Two vowels that come to stand in [[hiatus (linguistics)|hiatus]] because of that change contract into an overlong vowel — {{nowrap|''{{PIE|*-oHom}}'' 'genitive plural' > ''{{PIE|*-ôm}}'' > ''{{PIE|*-ǫ̂}}''; ''{{PIE|*-eh₂es}}'' 'eh₂-stem nom. pl.' > ''{{PIE|*-âs}}'' > {{lang|gem-x-proto|*-ôz}}}}
** In word-final position, the resulting long vowels remain distinct from (shorter than) the overlong vowels that were formed from PIE word-final long vowels — ''{{PIE|*-oh₂}}'' 'thematic 1st sg.' > {{lang|gem-x-proto|*-ō}}
* Laryngeals remain between consonants.
|-
|'''[[Cowgill's law of Germanic|Cowgill's law]]''': {{PIE|/h₃/}} (and possibly {{PIE|/h₂/}}) is strengthened to {{PIE|/g/}} between a sonorant and {{PIE|/w/}} — {{nowrap|''{{PIE|*n̥h₃mé}}'' 'us two' > ''{{PIE|*n̥h₃wé}}''{{Clarify|date=December 2024 |reason=Why does the *m become *w to begin with? No previous sound change mentioned in the article notes such a change}} > ''{{PIE|*ungwé}}'' > {{lang|gem-x-proto|*unk}}}}
|-
|'''Vocalisation of remaining laryngeals''': {{PIE|/H/}} > {{PIE|/ə/}} — {{nowrap|''{{PIE|*ph₂tḗr}}'' 'father' > ''{{PIE|*pətḗr}}'' > {{lang|gem-x-proto|*fadēr}}; ''{{PIE|*sámh₂dʰos}}'' 'sand' > ''{{PIE|*sámədʰos}}'' > {{lang|gem-x-proto|*samdaz}}}}
|-
|'''Velars are labialised''' by following {{PIE|/w/}}: ''{{PIE|*éḱwos}}'' 'horse' > ''{{PIE|*ékwos}}'' > ''{{PIE|*ékʷos}}'' > {{lang|gem-x-proto|*ehwaz}}
|-
|'''Labiovelars are delabialised''' next to {{PIE|/u/}} (or {{PIE|/un/}}) or before {{PIE|/t/}}:
* {{PIE|/kʷ/}} > {{PIE|/k/}} — ''{{PIE|*nókʷts}}'' 'night' > ''{{PIE|*nókts}}'' > ''{{lang|gem-x-proto|*nahts}}
* {{PIE|/gʷ/}} > {{PIE|/g/}} — ''{{PIE|*gʷémtis}}'' ~ ''{{PIE|*gʷm̥téys}}'' 'step, act of walking' > ''{{PIE|*gʷumtís}}'' > ''{{PIE|*gumtís}}'' > ''{{lang|gem-x-proto|*kumþiz}}'' 'coming, arrival'
* {{PIE|/gʷʰ/}} > {{PIE|/gʰ/}} — ''{{PIE|*gʷʰéntis}}'' ~ ''{{PIE|*gʷʰn̥tís}}'' 'killing' > ''{{PIE|*gʷʰuntís}}'' > ''{{PIE|*gʰuntís}}'' > ''{{lang|gem-x-proto|*gunþiz}}'' 'battle'
* This rule continued to operate into the Proto-Germanic period.
|}

====Early Proto-Germanic====
This stage began its evolution as a dialect of [[Proto-Indo-European language|Proto-Indo-European]] that had lost its laryngeals and had five long and six short vowels as well as one or two overlong vowels. The consonant system was still that of PIE minus palatovelars and laryngeals, but the loss of syllabic resonants already made the language markedly different from PIE proper. Mutual intelligibility might have still existed with other descendants of PIE, but it would have been strained, and the period marked the definitive break of Germanic from the other Indo-European languages and the beginning of Germanic proper, containing most of the sound changes that are now held to define this branch distinctively. This stage contained various consonant and vowel shifts, the loss of the contrastive accent inherited from PIE for a uniform accent on the first syllable of the word root, and the beginnings of the reduction of the resulting unstressed syllables.

{{anchor|Loss of word-final non-high short vowels}}
{| class="wikitable"
|-
|'''Loss of word-final non-high short vowels''' {{PIE|/e/}}, {{PIE|/a/}}, {{PIE|/o/}} — ''{{PIE|*wóyde}}'' '(s)he knows' > {{PIE|*wóyd}} > {{lang|gem-x-proto|*wait}}
* A {{PIE|/j/}} or {{PIE|/w/}} preceding the vowel is also lost — ''{{PIE|*tósyo}}'' 'of that' > ''{{PIE|*tós}}'' > {{lang|gem-x-proto|*þas}}
* Single-syllable words were not affected, but clitics were — ''{{PIE|*-kʷe}}'' 'and' > ''{{PIE|*-kʷ}}'' > {{lang|gem-x-proto|*-hw}}
* When the lost vowel was accented, the accent shifted to the preceding syllable — {{nowrap|''{{PIE|*n̥smé}}'' 'us' > ''{{PIE|*n̥swé}}'' > ''{{PIE|*unswé}}'' > ''{{PIE|*úns}}'' > {{lang|gem-x-proto|*uns}}}} (not {{lang|gem-x-proto|*unz}}, showing that loss occurred before Verner's law)
|-
|'''[[Grimm's law]]''': Chain shift of the three series of plosives. Voiced plosives had already been devoiced before a voiceless obstruent prior to this stage. Labiovelars were delabialised before {{PIE|/t/}}.
* Voiceless plosives become fricatives, unless preceded by another obstruent. In a sequence of two voiceless obstruents, the second obstruent remains a plosive.
** {{PIE|/p/}} > {{PIE|/ɸ/}} ({{PIE|f}}) — {{nowrap|''{{PIE|*ph₂tḗr}}'' 'father' > ''{{PIE|*fəþḗr}}'' > {{lang|gem-x-proto|*fadēr}}}}
** {{PIE|/t/}} > {{PIE|/θ/}} ({{PIE|þ}}) — {{nowrap|''{{PIE|*tód}}'' 'that' > ''{{PIE|*þód}}'' > {{lang|gem-x-proto|*þat}}}}
** {{PIE|/k/}} > {{PIE|/x/}} ({{PIE|h}}) — {{nowrap|''{{PIE|*kátus}}'' 'fight' > ''{{PIE|*háþus}}'' > {{lang|gem-x-proto|*haþuz}}; ''{{PIE|*h₂eǵs-}}'' 'axle' > (devoicing) ''{{PIE|*aks-}}'' > ''{{PIE|*ahs-}}'' > {{lang|gem-x-proto|*ahsō}}}}
** {{PIE|/kʷ/}} > {{PIE|/xʷ/}} ({{PIE|hw}}) — {{nowrap|''{{PIE|*kʷód}}'' 'what' > ''{{PIE|*hʷód}}'' > {{lang|gem-x-proto|*hwat}}}}
** Since the second of two obstruents is unaffected, the sequences {{PIE|/sp/}}, {{PIE|/st/}}, {{PIE|/sk/}}, and {{PIE|/skʷ/}} remain.
** The above also forms the [[Germanic spirant law]]:
*** {{PIE|/bt/}}, {{PIE|/bʰt/}}, {{PIE|/pt/}} > {{PIE|/ɸt/}} — {{nowrap|''{{PIE|*kh₂ptós}}'' 'grabbed' > ''{{PIE|*kəptós}}'' > ''{{PIE|*həftós}}'' > {{lang|gem-x-proto|*haftaz}}}} 'captive'
*** {{PIE|/gt/}}, {{PIE|/gʰt/}}, {{PIE|/kt/}} > {{PIE|/xt/}} — {{nowrap|''{{PIE|*oḱtṓw}}'' 'eight' > ''{{PIE|*oktṓw}}'' > ''{{PIE|*ohtṓw}}'' > {{lang|gem-x-proto|*ahtōu}}}}
*** {{PIE|/gʷt/}}, {{PIE|/gʷʰt/}}, {{PIE|/kʷt/}} > {{PIE|/xt/}} — {{nowrap|''{{PIE|*nokʷtm̥}}'' 'night, acc.' > ''{{PIE|*noktum}}'' > ''{{PIE|*nohtum}}'' > {{lang|gem-x-proto|*nahtų}}}}
* Voiced plosives are devoiced:
** {{PIE|/b/}} > {{PIE|/p/}} — {{nowrap|''{{PIE|*h₂ébōl}}'' 'apple' > ''{{PIE|*ápōl}}'' > {{lang|gem-x-proto|*aplaz}}}} (reformed as a-stem)
** {{PIE|/d/}} > {{PIE|/t/}} — {{nowrap|''{{PIE|*h₁dóntm̥}}'' 'tooth, acc.' > ''{{PIE|*tónþum}}'' > {{lang|gem-x-proto|*tanþų}}; ''{{PIE|*kʷód}}'' 'what' > ''{{PIE|*hʷód}}'' > {{lang|gem-x-proto|*hwat}}}}
** {{PIE|/g/}} > {{PIE|/k/}} — {{nowrap|''{{PIE|*wérǵom}}'' 'work' > ''{{PIE|*wérgom}}'' > ''{{PIE|*wérkom}}'' > {{lang|gem-x-proto|*werką}}}}
** {{PIE|/gʷ/}} > {{PIE|/kʷ/}} — {{nowrap|''{{PIE|*gʷémeti}}'' '(s)he will step, subj.' > ''{{PIE|*kʷémeþi}}'' > {{lang|gem-x-proto|*kwimidi}} '(s)he comes'}}
* Aspirated plosives become voiced plosives or fricatives (see below):
** {{PIE|/bʰ/}} > {{PIE|/b/}} ({{PIE|[b,β between vowels}}]) — {{nowrap|''{{PIE|*bʰéreti}}'' '(s)he is carrying' > ''{{PIE|*béreþi}}'' > {{lang|gem-x-proto|*biridi}}}}
** {{PIE|/dʰ/}} > {{PIE|/d/}} ({{PIE|[d,ð between vowels]}}) — {{nowrap|''{{PIE|*dʰóh₁mos}}'' 'thing put' > ''{{PIE|*dṓmos}}'' > {{lang|gem-x-proto|*dōmaz}} 'judgement'}}
** {{PIE|/gʰ/}} > {{PIE|/g/}} ({{PIE|[g,ɣ between vowels, possibly word initially]}}) — {{nowrap|''{{PIE|*gʰáns}}'' 'goose' > ''{{PIE|*gáns}}'' > {{lang|gem-x-proto|*gans}}}}
** {{PIE|/gʷʰ/}} > {{PIE|/gʷ/}} ({{PIE|[gʷ,ɣʷ between vowels,and possibly word-initially]}}) — {{nowrap|''{{PIE|*sóngʷʰos}}'' 'chant' > ''{{PIE|*sóngʷos}}'' > {{lang|gem-x-proto|*sangwaz}} 'song'}}
|-
|'''[[Verner's law]]''': Voiceless fricatives are voiced when preceded by an unaccented vowel, including cases where the vowel and fricative are separated by a sonorant (/n, m, r, l, j, w). This allophonic voicing became phonemic only after the regularization of stress placement (see below).
* {{PIE|/ɸ/}} > {{PIE|[β]}} — {{nowrap|''{{PIE|*upéri}}'' 'over' > ''{{PIE|*uféri}}'' > ''{{PIE|*ubéri}}'' > {{lang|gem-x-proto|*ubiri}}}}
* {{PIE|/θ/}} > {{PIE|[ð]}} — {{nowrap|''{{PIE|*tewtéh₂}}'' 'tribe' > ''{{PIE|*þewþā́}}'' > ''{{PIE|*þewdā́}}'' > {{lang|gem-x-proto|*þeudō}}}}
* {{PIE|/x/}} > {{PIE|[ɣ]}} — {{nowrap|''{{PIE|*h₂yuHn̥ḱós}}'' 'young' > ''{{PIE|*yunkós}}'' > ''{{PIE|*yunhós}}'' > ''{{PIE|*yungós}}'' > {{lang|gem-x-proto|*jungaz}}}} (with -z by analogy)
* {{PIE|/xʷ/}} > {{PIE|[ɣʷ]}} — {{nowrap|''{{PIE|*kʷekʷléh₂}}'' 'wheels (collective)' > ''{{PIE|*hʷehʷlā́}}'' > ''{{PIE|*hʷegʷlā́}}'' > {{lang|gem-x-proto|*hweulō}}}}
* {{PIE|/s/}} > {{PIE|[z]}} — ''{{PIE|*h₁régʷeses}}'' 'of darkness' > ''{{PIE|*rékʷeses}}'' > ''{{PIE|*rékʷezez}}'' > {{lang|gem-x-proto|*rikwiziz}}; ''{{PIE|*kʷékʷlos}}'' 'wheel' > ''{{PIE|*hʷéhʷlos}}'' > ''{{PIE|*hʷéhʷloz}}'' > {{lang|gem-x-proto|*hwehwlaz}}
* Some small words that were generally unaccented were also affected — ''{{PIE|*h₁ésmi}}'', unstressed ''{{PIE|*h₁esmi}}'' 'I am' > ''{{PIE|*esmi}}'' > ''{{PIE|*ezmi}}'' > {{lang|gem-x-proto|*immi}}; ''{{PIE|*h₁sénti}}'', unstressed ''{{PIE|*h₁senti}}'' 'they are' > ''{{PIE|*senþi}}'' > ''{{PIE|*sendi}}'' > {{lang|gem-x-proto|*sindi}} (the stressed variants, which would have become {{lang|gem-x-proto|*ismi}} and {{lang|gem-x-proto|*sinþi}}, were lost)
|-
|'''All words become stressed on their first syllable'''. The PIE contrastive accent is lost, phonemicising the voicing distinction created by Verner's law.
|-
|'''Word-initial {{PIE|/gʷ/}} > {{PIE|/b/}}''' {{dubious|date=November 2023}} — {{nowrap|{{PIE|*gʷʰédʰyeti}} "(s)he is asking for" > {{PIE|*gʷédyedi}} > {{PIE|*bédyedi}} > {{PIE|*bidiþi}} "(s)he asks, (s)he prays"}} (with -þ- by analogy)
|-
|'''Unstressed {{PIE|/owo/}} > {{PIE|/oː/}}''' — {{nowrap|''{{PIE|*-owos}}'' 'thematic first du.' > {{lang|gem-x-proto|*-ōz}}}}
|-
|'''Unstressed {{PIE|/ew/}} > {{PIE|/ow/}}''' before a consonant or word-finally — {{nowrap|''{{PIE|*-ews}}'' 'u-stem gen. sg.' > ''{{PIE|*-owz}}'' > {{lang|gem-x-proto|*-auz}}}}
|-
|{{anchor|Unstressed /e/ &gt; /i/}}'''Unstressed {{PIE|/e/}} > {{PIE|/i/}}''' except before {{PIE|/r/}} — ''{{PIE|*-éteh₂}}'' 'abstract noun suffix' > ''{{PIE|*-eþā}}'' > ''{{PIE|*-iþā}}'' > {{lang|gem-x-proto|*-iþō}}
* Unstressed {{PIE|/ej/}} contracts to {{PIE|/iː/}} — ''{{PIE|*-éys}}'' 'i-stem gen. sg.' > ''{{PIE|*-iys}}'' > ''{{PIE|*-īs}}'' > {{lang|gem-x-proto|*-īz}} (with -z by analogy)
* {{PIE|/e/}} before {{PIE|/r/}} later becomes {{PIE|/ɑ/}} but not until after the application of i-mutation.
* Some words that could be unstressed as a whole were also affected, often creating stressed/unstressed pairs — ''{{PIE|*éǵh₂}}'' 'I' > {{lang|gem-x-proto|*ek}} > unstressed {{lang|gem-x-proto|*ik}} (remaining beside stressed {{lang|gem-x-proto|*ek}})
|-
|{{anchor|Unstressed /ji/ &gt; /i/}}'''Unstressed {{PIE|/ji/}} > {{PIE|/i/}}''' — ''{{PIE|*légʰyeti}}'' '(s)he is lying down' ~ ''{{PIE|*légʰyonti}}'' 'they are lying down' > ''{{PIE|*legyidi}}'' ~ ''{{PIE|*legyondi}}'' > ''{{PIE|*legidi}}'' ~ ''{{PIE|*legyondi}}'' > {{lang|gem-x-proto|*ligiþi}} ~ {{lang|gem-x-proto|*ligjanþi}} (with -þ- by analogy)
* The process creates diphthongs from originally disyllabic sequences — ''{{PIE|*-oyend}}'' 'thematic optative 3pl' > ''{{PIE|*-oyint}}'' > ''{{PIE|*-oint}}'' > {{lang|gem-x-proto|*-ain}}; ''{{PIE|*áyeri}}'' 'in the morning' > ''{{PIE|*ayiri}}'' > {{lang|gem-x-proto|*airi}} 'early'; ''{{PIE|*tréyes}}'' 'three' > {{lang|gem-x-proto|*þreyiz}} > {{lang|gem-x-proto|*þreiz}} > {{lang|gem-x-proto|*þrīz}}
* The sequence {{PIE|/iji/}} becomes {{PIE|/iː/}} — ''{{PIE|*gʰósteyes}}'' 'strangers, nom. pl.' > ''{{PIE|*gostiyiz}}'' > ''{{PIE|*gostīz}}'' > {{lang|gem-x-proto|*gastīz}} 'guests'
|-
|'''Merging of non-high back vowels''':
* {{PIE|/o/}}, {{PIE|/a/}} > {{PIE|/ɑ/}} — ''{{PIE|*gʰóstis}}'' 'stranger' > ''{{PIE|*gostiz}}'' > {{lang|gem-x-proto|*gastiz}} 'guest'; ''{{PIE|*kápros}}'' 'he-goat' > {{lang|gem-x-proto|*hafraz}}
* {{PIE|/oː/}}, {{PIE|/aː/}} > {{PIE|/ɑː/}} — ''{{PIE|*dʰóh₁mos}}'' 'thing put' > ''{{PIE|*dōmoz}}'' > ''{{PIE|*dāmaz}}'' > {{lang|gem-x-proto|*dōmaz}} 'judgement'; ''{{PIE|*swéh₂dus}}'' 'sweet' > ''{{PIE|*swātuz}}'' > {{lang|gem-x-proto|*swōtuz}}
* {{PIE|/oːː/}}, {{PIE|/aːː/}} > {{PIE|/ɑːː/}} (â) — ''{{PIE|*séh₁mō}}'' 'seeds' > ''{{PIE|*sēmô}}'' > ''{{PIE|*sēmâ}}'' > {{lang|gem-x-proto|*sēmô}}; ''{{PIE|*-eh₂es}}'' 'eh₂-stem nom. pl.' > ''{{PIE|*-âz}}'' > {{lang|gem-x-proto|*-ôz}}
|}

====Late Proto-Germanic====
By this stage, Germanic had emerged as a distinctive branch and had undergone many of the sound changes that would make its later descendants recognisable as Germanic languages. It had shifted its consonant inventory from a system that was rich in plosives to one containing primarily fricatives, had lost the PIE mobile pitch accent for a predictable stress accent, and had merged two of its vowels. The stress accent had already begun to cause the erosion of unstressed syllables, which would continue in its descendants. The final stage of the language included the remaining development until the breakup into dialects and, most notably, featured the development of nasal vowels and the start of [[Germanic umlaut|umlaut]], another characteristic Germanic feature.

{| class="wikitable"
|-
|{{anchor|Word-final /m/ &gt; /n/}}'''Word-final {{PIE|/m/}} > {{PIE|/n/}}''' — ''{{PIE|*tóm}}'' 'that, acc. masc.' > {{lang|gem-x-proto|*þam}} > {{lang|gem-x-proto|*þan}} 'then'; ''{{PIE|*-om}}'' 'a-stem acc. sg.' > {{lang|gem-x-proto|*-am}} > {{lang|gem-x-proto|*-an}} > {{lang|gem-x-proto|*-ą}}
|-
|'''{{PIE|/m/}} > {{PIE|/n/}} before dental consonants''' — ''{{PIE|*ḱm̥tóm}}'' 'hundred' > ''{{PIE|*humdan}}'' > ''{{PIE|*hundan}}'' > {{lang|gem-x-proto|*hundą}}; ''{{PIE|*déḱm̥d}}'' 'ten' > ''{{PIE|*tehumt}}'' > ''{{PIE|*tehunt}}'' > {{lang|gem-x-proto|*tehun}}
|-
|{{anchor|Word-final /n/ is lost}}'''Word-final {{PIE|/n/}} is lost''' after unstressed syllables, and the preceding vowel is nasalised — ''{{PIE|*-om}}'' 'a-stem acc. sg.' > ''{{PIE|*-am}}'' > ''{{PIE|*-an}}'' > {{lang|gem-x-proto|*-ą}}; ''{{PIE|*-eh₂m}}'' > ''{{PIE|*-ān}}'' > {{lang|gem-x-proto|*-ą̄}} > {{lang|gem-x-proto|*-ǭ}}; ''{{PIE|*-oHom}}'' 'genitive plural' > ''{{PIE|*-ân}}'' > ''{{PIE|*-ą̂}}'' > {{lang|gem-x-proto|*-ǫ̂}}
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|'''Nasal {{PIE|/ẽː/}} is lowered''' to {{PIE|/ɑ̃ː/}} — ''{{PIE|*dʰédʰeh₁m}}'' 'I was putting' > {{lang|gem-x-proto|*dedēn}} > {{lang|gem-x-proto|*dedę̄}} > {{lang|gem-x-proto|*dedą̄}} > {{lang|gem-x-proto|*dedǭ}}
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|'''Elimination of {{PIE|/ə/}}''':
* Unstressed {{PIE|/ə/}} is lost between consonants — ''{{PIE|*sámh₂dʰos}}'' 'sand' > {{lang|gem-x-proto|*samədaz}} > {{lang|gem-x-proto|*samdaz}}; ''{{PIE|*takéh₁-}}'' 'to be silent' > (with added suffix) ''{{PIE|*takəyónti}}'' 'they are silent' > {{lang|gem-x-proto|*þagəyanþi}} > {{lang|gem-x-proto|*þagyanþi}} > {{lang|gem-x-proto|*þagjanþi}}
* {{PIE|/ə/}} > {{PIE|/ɑ/}} elsewhere — ''{{PIE|*ph₂tḗr}}'' 'father' > {{lang|gem-x-proto|*fədēr}} > {{lang|gem-x-proto|*fadēr}}; ''{{PIE|*takéh₁-}}'' 'to be silent' > (with added suffix) ''{{PIE|*takəyéti}}'' '(s)he is silent' > {{lang|gem-x-proto|*þagəyiþi}} > {{lang|gem-x-proto|*þagəiþi}} > {{lang|gem-x-proto|*þagaiþi}}
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|'''Assimilation of sonorants''':
* {{PIE|/nw/}} > {{PIE|/nn/}} — ''{{PIE|*ténh₂us}}'' 'thin' ~ fem. ''{{PIE|*tn̥h₂éwih₂}}'' > ''{{PIE|*tn̥h₂ús}}'' ~ ''{{PIE|*tn̥h₂wíh₂}}'' > {{lang|gem-x-proto|*þunus}} ~ {{lang|gem-x-proto|*þunwī}} > {{lang|gem-x-proto|*þunus}} ~ {{lang|gem-x-proto|*þunnī}} > {{lang|gem-x-proto|*þunnuz}} ~ {{lang|gem-x-proto|*þunnī}}
* {{PIE|/ln/}} > {{PIE|/ll/}} — {{nowrap|''{{PIE|*pl̥h₁nós}}'' 'full' > {{lang|gem-x-proto|*fulnos}} > {{lang|gem-x-proto|*fullos}} > {{lang|gem-x-proto|*fullaz}}}}.{{sfn|Ringe|2006|p=139-140}} This development postdated contact with the [[Samic languages]], as is shown by the loanword {{lang|gem-x-proto|*pulna}} > [[Proto-Samic]] {{lang|mis|*polnē}} 'hill(ock), mound'.<ref name="Aikio06">{{cite journal|first=Ante|last=Aikio|title=On Germanic-Saami contacts and Saami prehistory|year=2006|journal=Suomalais-Ugrilaisen Seuran Aikakauskirja|volume=91|pages=9–55}}</ref>
* {{PIE|/zm/}} > {{PIE|/mm/}} — {{nowrap|''{{PIE|*h₁esmi}}'' 'I am, unstr.' > ''{{PIE|*ezmi}}'' > ''{{PIE|*emmi}}'' > {{lang|gem-x-proto|*immi}}}}
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|{{anchor|Loss of word-final /t/}}'''Loss of word-final {{PIE|/t/}}''' after unstressed syllables — ''{{PIE|*déḱm̥d}}'' 'ten' > {{lang|gem-x-proto|*tehunt}} > {{lang|gem-x-proto|*tehun}}; ''{{PIE|*bʰéroyd}}'' '(s)he would carry, subj.' > {{lang|gem-x-proto|*berayt}} > {{lang|gem-x-proto|*berai}}; ''{{PIE|*mélid}}'' ~ ''{{PIE|*mélit-}}'' 'honey' > {{lang|gem-x-proto|*melit}} ~ {{lang|gem-x-proto|*melid-}} > {{lang|gem-x-proto|*meli}} ~ {{lang|gem-x-proto|*melid-}} > {{lang|gem-x-proto|*mili}} ~ {{lang|gem-x-proto|*milid-}}
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|'''{{PIE|/ɣʷ/}} > {{PIE|/w/}}''', sometimes {{PIE|/ɣ/}} — ''{{PIE|*snóygʷʰos}}'' 'snow' > {{lang|gem-x-proto|*snaygʷaz}} > {{lang|gem-x-proto|*snaiwaz}}; ''{{PIE|*kʷekʷléh₂}}'' 'wheels (collective)' > ''{{PIE|*hʷegʷlā}}'' > ''{{PIE|*hʷewlā}}'' > {{lang|gem-x-proto|*hweulō}}
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|'''Long a is raised''':
* {{PIE|/ɑː/}} > {{PIE|/ɔː/}} — ''{{PIE|*dʰóh₁mos}}'' 'thing put' > {{lang|gem-x-proto|*dāmaz}} > {{lang|gem-x-proto|*dōmaz}} 'judgement'; ''{{PIE|*swéh₂dus}}'' 'sweet' > {{lang|gem-x-proto|*swātuz}} > {{lang|gem-x-proto|*swōtuz}}
* {{PIE|/ɑːː/}} > {{PIE|/ɔːː/}} — ''{{PIE|*séh₁mō}}'' 'seeds' > {{lang|gem-x-proto|*sēmâ}} > {{lang|gem-x-proto|*sēmô}}; ''{{PIE|*-eh₂es}}'' 'eh₂-stem nom. pl.' > {{lang|gem-x-proto|*-âz}} > {{lang|gem-x-proto|*-ôz}}
* That followed the earliest contact with the Romans since Latin {{lang|la|Rōmānī}} was borrowed as {{lang|gem-x-proto|*Rūmānīz}} and then shifted to {{lang|gem-x-proto|*Rūmōnīz}}.
* Finnic loanwords preceding the change are also known:
** [[Finnish language|Finnish]] {{lang|fi|hake-}} 'to seek', from early Proto-Germanic {{lang|gem-x-proto|*sākija-}} (later {{lang|gem-x-proto|*sōkija-}})
** Finnish {{lang|fi|raha}} 'money', from early Proto-Germanic {{lang|gem-x-proto|*skrahā}} 'squirrel skin' (later {{lang|gem-x-proto|*skrahō}})
** Finnish {{lang|fi|kavio}} 'hoof', from Pre-Proto-Germanic ''{{PIE|*kāpa-}}'' 'hoof' (later {{lang|gem-x-proto|*hōfa-}})
** Finnish {{lang|fi|lieka}} 'tether', from Pre-Proto-Germanic ''{{PIE|*lēgā-}}'' 'to lie, be at rest' (later {{lang|gem-x-proto|*lēgō-}}, as demonstrated by the later loan {{lang|fi|lieko}} 'windfallen or decayed tree')
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|{{anchor|Early i-mutation}}'''Early [[i-mutation]]''': {{PIE|/e/}} > {{PIE|/i/}} when followed by {{PIE|/i/}} or {{PIE|/j/}} in the same or next syllable — ''{{PIE|*bʰéreti}}'' '(s)he is carrying' > {{lang|gem-x-proto|*beridi}} > {{lang|gem-x-proto|*biridi}}; ''{{PIE|*médʰyos}}'' 'middle' > {{lang|gem-x-proto|*medyaz}} > {{lang|gem-x-proto|*midjaz}}; ''{{PIE|*néwios}}'' 'new' > {{lang|gem-x-proto|*newyaz}} > {{lang|gem-x-proto|*niwjaz}}
* This eliminates the remaining {{PIE|/ei/}}, changing it to {{PIE|/iː/}} — ''{{PIE|*deywós}}'' 'god' > {{lang|gem-x-proto|*teiwaz}} (attested as ''teiva-'' in the [[Negau helmet]]) > {{lang|gem-x-proto|*Tīwaz}} '[[Týr]]'; ''{{PIE|*tréyes}}'' 'three' > {{lang|gem-x-proto|*þreiz}} > {{lang|gem-x-proto|*þrīz}}
* A number of loanwords in the Finnic and Samic demonstrate earlier *e, e.g.
** Finnish {{lang|fi|teljo}} 'thwart', from early Proto-Germanic {{Lang|gem-x-proto|*þeljō}} (later {{Lang|gem-x-proto|*þiljō}})
** Finnish {{lang|fi|menninkäinen}} 'goblin', from early Proto-Germanic {{lang|gem-x-proto|*menþingō}} (later {{lang|gem-x-proto|*minþingō}})
** [[Northern Sami]] {{lang|se|deahkki}} 'thick meat', from early Proto-Germanic {{lang|gem-x-proto|*þekkwiz}} 'thick' (later {{lang|gem-x-proto|*þikkwiz}})<ref name="Aikio06"/>
** Northern Sami {{lang|se|jievja}} 'white (of animal, or hair)', from early Proto-Germanic {{lang|gem-x-proto|*heują}} (later {{lang|gem-x-proto|*hiują}})
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|{{anchor|Pre-nasal raising}}'''{{PIE|/e/}} > {{PIE|/i/}}''' when followed by a syllable-final nasal — {{PIE|*en}} 'in' > {{lang|gem-x-proto|*in}}; {{lang|gem-x-proto|*séngʷʰeti}} '(s)he chants' > {{lang|gem-x-proto|*sengʷidi}} > {{lang|gem-x-proto|*singwidi}} '(s)he sings'
* Finnic loanwords demonstrating earlier *e are again known: Finnish {{lang|fi|rengas}} 'ring', from early Proto-Germanic {{lang|gem-x-proto|*hrengaz}} (later {{lang|gem-x-proto|*hringaz}})
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|'''{{PIE|/j/}} is lost between vowels''' except after {{PIE|/i/}} and {{PIE|/w/}} (but it is lost after syllabic {{PIE|/u/}}). The two vowels that come to stand in hiatus then contract to long vowels or diphthongs — ''{{PIE|*-oyh₁m̥}}'' 'thematic optative 1sg sg.' > {{lang|gem-x-proto|*-oyum}} > ''{{PIE|*-ayų}}'' > {{lang|gem-x-proto|*-aų}}; ''{{PIE|*h₂eyeri}}'' 'in the morning' > {{lang|gem-x-proto|*ayiri}} > {{lang|gem-x-proto|*airi}} 'early'
* This process creates a new {{PIE|/ɑː/}} from earlier {{PIE|/ɑjɑ/}} — ''{{PIE|*steh₂-}}'' 'to stand' > (with suffix added) ''{{PIE|*sth₂yónti}}'' 'they stand' > {{lang|gem-x-proto|*stayanþi}} > {{lang|gem-x-proto|*stānþi}}
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|{{anchor|/n/ is lost before /x/}}'''{{PIE|/n/}} is lost before {{PIE|/x/}}''', causing [[compensatory lengthening]] and nasalisation of the preceding vowel — ''{{PIE|*ḱónketi}}'' '(s)he hangs' > {{lang|gem-x-proto|*hanhidi}} (phonetically {{lang|gem-x-proto|[ˈxɑ̃ːxiði]}})
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