Abstract
In this study data from the first six months of 12 children's multiword speech were used to test the validity of Valian's (1991) syntactic performance-limitation account and Tomasello's (1992) verb-island account of early multiword speech with particular reference to the development of the English verb category. The results provide evidence for appropriate use of verb morphology, auxiliary verb structures, pronoun case marking, and SVO word order from quite early in development. However, they also demonstrate a great deal of lexical specificity in the children's use of these systems, evidenced by a lack of overlap in the verbs to which different morphological markers were applied, a lack of overlap in the verbs with which different auxiliary verbs were used, a disproportionate use of the first person singular nominative pronoun I, and a lack of overlap in the lexical items that served as the subjects and direct objects of transitive verbs. These findings raise problems for both a syntactic performance-limitation account and a strong verb-island account of the data and suggest the need to develop a move general lexicalist account of early multiword speech that explains why some words come to function as "islands" of organization in the child's grammar and others do not.
