An Evaluation of the Facilitative Effects of Inverted Yes-No Questions on the Acquisition of Auxiliary Verbs

According to the Auxiliary Clarification Hypothesis (ACH), yes-no questions with sentence-initial auxiliaries (i.e., inverted questions) facilitate children's initial acquisition of auxiliary verbs. Sixteen 3-year-old children with specific language impairment (SLI) and 18 2-year-olds with typical language (TL) participated in an experiment to evaluate the ACH. The children were not yet making use of auxiliaries. Half of the children participated in twenty 30-min "enrichment" sessions over a 2-month period, during which an assistant produced 30 inverted question recasts in response to the child's own utterances. Fifteen question recasts contained the auxiliary is, and 15 contained the modal will. The other half of the children participated in play sessions but were not exposed to inverted is and will questions. Contrary to predictions based on the ACH, the results revealed no positive effects of the enrichment for is, for will, or for the broader BE and Modal auxiliary categories for either group of children. The children with TL demonstrated advantages over the children with SLI for the general category of BE forms but not for the category of Modals. Inverted questions may be too complex to foster the initial acquisition of auxiliaries in children not already using them productively.