Lexical aspect and the use of verb morphology by children with specific language impairment.

Purpose: Many typically developing children first use inflections such as -ed with verb predicates whose meanings are compatible with the functions of the inflection (e.g., using -ed when describing events of brief duration with clear end points, such as dropped). This tendency is assumed to be beneficial for development. In this study, the authors examine whether preschool-aged children with specific language impairment (SLI) show a similar tendency.

Method: Sixteen children in each of three groups participated-children with SLI, typically developing children matched for age (TD-A), and younger typically developing children matched for mean length of utterance (TD-MLU). The children described actions in contexts that promoted either past tense -ed or progressive aspect -ing in past contexts. Half of the verb predicates referred to events of brief duration with distinct endpoints (e.g., drop), and half referred to events of considerable duration with less distinct points of termination (e.g., play).

Results: Both the TD-A children and the TD-MLU children used -ed with verb predicates of the first type more consistently than they did with verb predicates of the second type. They showed the reverse pattern for -ing. The children with SLI did not show any effects according to the verb predicate type. However, although the children with SLI made less overall use of -ed than did both groups of TD children, they differed only from the TD-A children in their overall use of -ing.

Conclusion: Difficulties with tense-related morphology may be compounded in children with SLI if they fail to make use of associations between the lexical aspect of verb predicates and the grammatical function of the accompanying inflections. The authors argue that the advantages of using these associations as a starting point in acquisition may be especially important in the case of -ed. Additional studies of children with SLI are clearly needed, including those that employ longitudinal, naturalistic data.