Abstract
This study examined patterns of auxiliary provision and omission for the auxiliaries BE and HAVE in a longitudinal data set from 11 children between the ages of two and three years. Four possible explanations for auxiliary omission - a lack of lexical knowledge, performance limitations in production, the Optional Infinitive hypothesis, and patterns of auxiliary use in the input - were examined. The data suggest that although none of these accounts provides a full explanation for the pattern of auxiliary use and nonuse observed in children's early speech, integrating input-based and lexical learning-based accounts of early language acquisition within a constructivist approach appears to provide a possible framework in which to understand the patterns of auxiliary use found in the children's speech. The implications of these findings for models of children's early language acquisition are discussed.
