Effects of Verb Familiarity on Finiteness Marking in Children with SLI

Children must acquire multiple language dimensions to ultimately achieve adult levels of language competence. Two such language dimensions, finiteness marking and the verb lexicon, are considered areas of weakness in specific language impairment (SLI). Given these weaknesses, the question arises of whether these two dimensions are related in children with SLI and/or typically developing children. One way to examine this question is to assess the hypothesis that verb familiarity influences finiteness marking accuracy. A sentence imitation task was developed to examine this hypothesis. In sentence imitation tasks, a child is asked to repeat a sentence verbatim. Sentence imitation has been proposed as an index of children's generative use of grammar (Child Grammar Account). An alternative proposal is that sentence imitation measures verbal memory instead of language ability (Verbal Memory Account).;The sentence imitation task employed in the current study allowed estimates of finiteness marking and the verb lexicon while examining whether verb familiarity influences finiteness marking. Imitations were coded and analyzed for overall sentence accuracy and deviations from the target sentence in individual clausal components (i.e., finiteness marking and the verb root). The coding system designed for this study also set up a comparison of the two proposed accounts of sentence imitation. Three groups of children completed the sentence imitation task: 20 children with SLI (5-years old), 23 age-equivalent control children (AE; 5-years old) and 16 language-equivalent control children (LE; 3-years old). The AE group was more accurate than each of the SLI and LE groups (who performed similarly) on overall sentence imitation accuracy, finiteness marking accuracy and verb root imitation accuracy. Familiar verbs conferred an advantage on overall sentence imitation, finiteness marking and verb root imitation accuracy as well. Results also reported group x condition interactions for finiteness marking and verb root imitation. Patterns of deviations from the target sentence support the Child Grammar Account of sentence imitation, but not the Verbal Memory Account. Overall, study findings are consistent with expectations based on the literature and support the proposal that verb familiarity affects finiteness marking.