This study explored responsive and linguistic parent input features during parent-child interactions and investigated how four input categories related to children’s production of diverse, simple sentences. Of primary interest was parent use of responsive, simple declarative input sentences. Responsive and linguistic features of parent input to 20 typically developing toddlers at 1;9 were coded during play in a laboratory playroom, then classified into four input categories: responsive, declarative, responsive declarative, and neither responsive nor simple declarative. The percentage of each input category was related to child sentence diversity at 2;6 using Spearman correlations. Parent use of responsive declarative and declarative utterances were both rare. Responsive input was positively correlated with child sentence diversity, and the neither category was negatively correlated with child sentence diversity. The findings provide new support for the importance of balanced conversational turns. Implications for defining both how input is delivered and its linguistic content are discussed.
