Parents are often a good source of information, introducing children to how the world around them is described and explained in terms of cause-and-effect relations. Parents also vary in their speech, and these variations can predict children’s later language skills. Being born preterm might be related to such parent-child interactions. The present longitudinal study investigated parental causal language use in Turkish, a language with particular causative morphology, across three time points when preterm and full-term children were 14-, 20-, and 26-months-old. In general, although preterm children heard fewer words overall, there were no differences between preterm and full-term groups in terms of the proportion of causal language input. Parental causal language input increased from 20 to 26 months, while the amount of overall verbal input remained the same. These findings suggest that neonatal status can influence the amount of overall parental talk, but not parental use of causal language.

How does parental causal input relate to children’s later comprehension of causal verbs? Causal constructions in verbs differ across languages. Turkish has both lexical and morphological causatives. We asked whether (1) parental causal language input varied for different types of play (guided vs. free play), (2) early parental causal language input predicted children’s causal verb understanding. Twenty-nine infants participated at three timepoints. Parents used lexical causatives more than morphological ones for guided-play for both timepoints, but for free-play, the same difference was only found at Time 2. For Time 3, children were tested on a verb comprehension and a vocabulary task. Morphological causative input, but not lexical causative input, during free-play predicted children’s causal verb comprehension. For guided-play, the same relation did not hold. Findings suggest a role of specific types of causal input on children’s understanding of causal verbs that are received in certain play contexts.