Sequence and System in the Acquisition of Tense and Agreement

• Published in: Journal of speech, language, and hearing research Vol. 55; no. 4; pp. 1007 - 1021
• Main Authors: Rispoli, Matthew, Hadley, Pamela A, Holt, Janet K
• Format: Journal Article
• Language: English
• Published: United States American Speech-Language-Hearing Association (ASHA) 01-08-2012
• Subjects: Child Language; Child, Preschool; Female; Grammar; Humans; Infant; Language Acquisition; Language Development; Language Tests; Longitudinal Studies; Male; Morphemes; Morphology (Languages); Semantics; Speech; Speech Production Measurement; Syntax; Toddlers; Verbal Behavior
• ISSN: 1092-4388; 1558-9102
• DOI: 10.1044/1092-4388(2011/10-0272)

Purpose: The relatedness of tense morphemes in the language of children younger than 3 years of age is a matter of controversy. Generativist accounts predict that the morphemes will be related, whereas usage-based accounts predict the absence of relationships. This study focused on the increasing productivity of the 5 morphemes in the tense productivity score (copula BE, third-person singular present--"3s", past--"ed", auxiliary DO, auxiliary BE; Hadley & Short, 2005) and their relationship to one another. Method: Twenty typically developing children were observed longitudinally from 21 to 33 months of age. One hour of naturalistic caregiver-child interaction sampled every 3 months was analyzed. Results: Copula BE was more productive than all other morphemes from age 27 months onward. Auxiliary BE was significantly less productive than--"3s",--"ed", and DO from age 27 months onward. Evaluation of third-person singular tense morphemes at age 33 months revealed that the productivity scores of copula "is",--"3s", and "does" were all correlated. Conclusions: There is sequence and simultaneity in development that no prior framework has fully explained, as well as evidence of cross-morpheme relationships. In this article, the authors interpret these findings as support for the gradual morphosyntactic learning hypothesis (Rispoli & Hadley, 2011; Rispoli, Hadley, & Holt, 2009).