Explains the differences between constituency and dependency theories for structural linguistics. Reasons are provided for why the former has been indirectly responsible for the neglect of lexical acquisition in language acquisition research and for proposing a notation based on dependency theory for describing learners' segmentation of initially…

Discusses variation in interlanguage and suggests two hypotheses to explain such variation as multiple internal representations of a form and processing errors. Suggests that second language learners can initially represent new forms as prototype schemas, and that such non-discrete representations are a third source of variation in interlanguage.…