Children’s early negative auxiliaries are true auxiliaries

Abstract

ABSTRACT This study investigates young children’s acquisition of functional categories through their use of negative words and negative auxiliaries in particular. Drawing from CHILDES, we analyze twelve months of spontaneous speech by 14 children (youngest age 1;9, oldest age 3;1) and their mothers, in order to assess whether children’s earliest negative productions are morphological combinations and reflect possession of abstract syntactic categories or are instead input-driven formulae. In five analyses we show that (i) two-year-olds use a wide and overlapping range of negative and positive auxiliaries; (ii) the range of the negative auxiliaries children produce is strongly correlated with the range of the positive auxiliaries they produce; (iii) children’s most common negative auxiliary, don’t, is used grammatically with respect to the syntactic category being negated and with respect to overt markings of tense; (iv) children’s subject agreement errors with don’t are mirrored by subject agreement errors with do, have, and haven’t; and (v) children omit auxiliaries with not at rates that cannot be attributed to properties of their input. Our findings support the hypothesis that children’s earliest negations are syntactically adult-like and reflect the possession of abstract syntactic categories. By age 2, English-learning children productively combine auxiliary, negation, and tense categories and syntactically differentiate different negative morphemes.