Key points are not available for this paper at this time.
ABSTRACT Samples of the speech addressed by adults to a socially representative sample of 2-year-olds in naturally occurring contexts of interaction were analysed with respect to syntactic, semantic, pragmatic and discourse features to determine which features were most strongly associated with gain by the children on a variety of measures of language development over the ensuing 9 months. Following a principal components analysis of the adult speech variables, the most highly loading variables on the first six components were correlated with children's gain scores. Polar interrogatives, directives and extending utterances were all found to be associated with at least one measure of development. The results are if interpreted as evidence of reciprocal, rather than one-way facilitation.
Barnes et al. (Tue,) studied this question.