Subject case marking and verb morphology in normally developing and specifically language-impaired children.

Recent theories of language development propose a direct relationship between children's use of verb morphology and their use of subject case pronouns. Such proposals might contribute to an understanding of specifically language-impaired (SLI) children's difficulties. These children's extraordinary problems with verb morphology are well documented, and preliminary evidence indicates frequent pronoun case errors (e.g., her for she) in their speech. Thus, it is possible that a collection of difficulties may be linked to a common source in these children. The objectives of this study were to determine: (a) whether subject case marking, as well as verb morphology was more limited in the speech of a group of SLI children than in the speech of a younger group of normally developing (ND) children matched for mean utterance length; (b) whether a relationship between the use of subject case marking and the use of verb morphology existed in the speech of the ND children; and, if so, (c) whether this relationship is evident in the SLI children as well, in spite of their more limited use of these features. The results revealed that the SLI children were more limited than the ND children in the use of both subject case marking and verb morphology. However, a relationship between the two types of usage was found in both groups of children.