Editing Language acquisition (section)

==Vocabulary acquisition==
{{main|Vocabulary learning}}
Learning a new word, that is, learning to speak this word and speak it on the appropriate occasions, depends upon many factors. First, the learner needs to be able to hear what they are attempting to pronounce. Also required is the capacity to engage in [[speech repetition]].<ref name="Bloom 1974">{{cite journal |last1=Bloom |first1=Lois |last2=Hood |first2=Lois |last3=Lightbown |first3=Patsy |title=Imitation in language development: If, when, and why |journal=Cognitive Psychology |date=July 1974 |volume=6 |issue=3 |pages=380–420 |doi=10.1016/0010-0285(74)90018-8 }}</ref><ref name="Miller 1977">{{cite book |author=Miller, George A. |title=Spontaneous apprentices: children and language |publisher=Seabury Press |location=New York |year=1977 |isbn=978-0-8164-9330-2 |oclc=3002566 |url-access=registration |url=https://archive.org/details/spontaneousappre00mill }}</ref><ref name="Masur 1995">{{cite journal|author=Masur EF|year=1995|title=Infants' early verbal imitation and their later lexical development|journal=Merrill-Palmer Quarterly|volume=41|issue=3|pages=286–306|oclc=89395784}}</ref><ref name="Gathercole 1989">{{cite journal |last1=Gathercole |first1=Susan E |last2=Baddeley |first2=Alan D |title=Evaluation of the role of phonological STM in the development of vocabulary in children: A longitudinal study |journal=Journal of Memory and Language |date=April 1989 |volume=28 |issue=2 |pages=200–213 |doi=10.1016/0749-596X(89)90044-2 }}</ref> Children with reduced ability to repeat non-words (a marker of speech repetition abilities) show a slower rate of vocabulary expansion than children with normal ability.<ref name="Gathercole 2006">{{cite journal |last1=Gathercole |first1=Susan E. |title=Nonword repetition and word learning: The nature of the relationship |journal=Applied Psycholinguistics |date=October 2006 |volume=27 |issue=4 |pages=513–543 |id={{ProQuest|1613100017}} |doi=10.1017/S0142716406060383 }}</ref> Several computational models of vocabulary acquisition have been proposed.<ref name="Prahlad">{{cite journal |author1=Gupta Prahlad |author2=MacWhinney Brian | year = 1997 | title = Vocabulary acquisition and verbal short-term memory: Computational and neural bases | journal = Brain and Language | volume = 59 | issue = 2| pages = 267–333 | doi = 10.1006/brln.1997.1819 | pmid = 9299067 }}</ref><ref name="Regier 2003">{{cite journal |last1=Regier |first1=Terry |title=Emergent constraints on word-learning: a computational perspective |journal=Trends in Cognitive Sciences |date=June 2003 |volume=7 |issue=6 |pages=263–268 |doi=10.1016/s1364-6613(03)00108-6 |pmid=12804693 }}</ref><ref name="Regier 2005">{{cite journal |last1=Regier |first1=Terry |title=The Emergence of Words: Attentional Learning in Form and Meaning |journal=Cognitive Science |date=12 November 2005 |volume=29 |issue=6 |pages=819–865 |doi=10.1207/s15516709cog0000_31 |pmid=21702796 }}</ref><ref>{{cite journal |author1=Hadzibeganovic Tarik |author2=Cannas Sergio A | year = 2009 | title = A Tsallis' statistics based neural network model for novel word learning | journal = Physica A | volume = 388 | issue = 5| pages = 732–746 | doi = 10.1016/j.physa.2008.10.042 | bibcode = 2009PhyA..388..732H }}</ref><ref>{{cite journal |last1=Roy |first1=Deb K. |last2=Pentland |first2=Alex P. |title=Learning words from sights and sounds: a computational model |journal=Cognitive Science |date=January 2002 |volume=26 |issue=1 |pages=113–146 |doi=10.1207/s15516709cog2601_4 }}</ref><ref>{{cite journal |last1=Fazly |first1=Afsaneh |last2=Alishahi |first2=Afra |last3=Stevenson |first3=Suzanne |title=A Probabilistic Computational Model of Cross-Situational Word Learning |journal=Cognitive Science |date=August 2010 |volume=34 |issue=6 |pages=1017–1063 |doi=10.1111/j.1551-6709.2010.01104.x |pmid=21564243 }}</ref><ref>{{cite journal |last1=Yu |first1=Chen |last2=Ballard |first2=Dana H. |title=A unified model of early word learning: Integrating statistical and social cues |journal=Neurocomputing |date=August 2007 |volume=70 |issue=13–15 |pages=2149–2165 |doi=10.1016/j.neucom.2006.01.034 }}</ref> Various studies have shown that the size of a child's vocabulary by the age of 24 months correlates with the child's future development and language skills. If a child knows fifty or fewer words by the age of 24 months, he or she is classified as a [[Language delay|late-talker]], and future language development, like vocabulary expansion and the organization of grammar, is likely to be slower and stunted.{{citation needed|date=December 2012}}

Two more crucial elements of vocabulary acquisition are word segmentation and statistical learning (described above).  Word segmentation, or the ability to break down words into syllables from fluent speech can be accomplished by eight-month-old infants.<ref name="Saffran 1996 1926–1928"/> By the time infants are 17 months old, they are able to link meaning to segmented words.<ref name="Graf Estes 2007 254–260"/>

Recent evidence also suggests that motor skills and experiences may influence vocabulary acquisition during infancy. Specifically, learning to sit independently between 3 and 5 months of age has been found to predict receptive vocabulary at both 10 and 14 months of age,<ref>{{cite journal |author1=Libertus Klaus |author2=Violi Dominic A | year = 2016 | title = Sit to talk: Relation between motor skills and language development in infancy | journal = Frontiers in Psychology | volume = 7| pages =  475| doi = 10.3389/fpsyg.2016.00475 | pmid=27065934|pmc=4815289|doi-access=free }}</ref> and independent walking skills have been found to correlate with language skills at around 10 to 14 months of age.<ref>{{cite journal | vauthors = Walle Eric A, Campos Joe J | year = 2014 | title = Infant language development is related to the acquisition of walking | journal = Developmental Psychology | volume = 50 | issue = 2 | pages = 336–348 | doi = 10.1037/a0033238 | pmid = 23750505 }}</ref><ref>{{cite journal | vauthors = He M, Walle Eric A, Campos Joe J | year = 2015 | title = A cross-national investigation of the relationship between infant walking and language development | journal = Infancy | volume = 20 | issue = 3 | pages = 283–305 | doi = 10.1111/infa.12071 | doi-access = free }}</ref> These findings show that language acquisition is an embodied process that is influenced by a child's overall motor abilities and development. Studies have also shown a correlation between [[Socioeconomic status#Language development|socioeconomic status and vocabulary acquisition]].<ref>{{cite journal |last1=Letts |first1=Carolyn |last2=Edwards |first2=Susan |last3=Sinka |first3=Indra |last4=Schaefer |first4=Blanca |last5=Gibbons |first5=Wendy |title=Socio-economic status and language acquisition: children's performance on the new Reynell Developmental Language Scales |journal=International Journal of Language & Communication Disorders |date=March 2013 |volume=48 |issue=2 |pages=131–143 |doi=10.1111/1460-6984.12004 |pmid=23472954 |url=https://oro.open.ac.uk/35325/1/__Appleton_irs54_My%20Documents_Reynell_Publications_SESPaper_resubmission.pdf }}</ref>