Prosodic cues in infant-directed speech facilitate young children's conversational turn predictions.

Experienced language users are able to predict when conversational turns approach completion, which allows them to attend to and comprehend their interlocutor's speech while planning and accurately timing their response. Adults primarily rely on lexico-syntactic cues to make such predictions, but it remains unknown what cues support these predictions in young children whose lexico-syntactic competence is still developing. This study assessed children's reliance on prosodic cues, specifically when predicting conversational turn transitions in infant-directed speech (IDS), the speech register that they encounter in day-to-day interactions that is characterized by exaggerated prosody compared with adult-directed speech (ADS). Young children (1- and 3-year-olds) completed an anticipatory looking paradigm in which their gaze patterns were recorded while they observed conversations that were produced in IDS or ADS and that contained prosodically complete utterances (lexico-syntactic and prosodic cues) and prosodically incomplete utterances (only lexico-syntactic cues). The 1-year-olds anticipated more turns that were signaled by prosodic cues (i.e., prosodically complete utterances) only in IDS, whereas the 3-year-olds did so in both IDS and ADS. These findings indicate that children anticipate the completion of conversational turns by relying on prosodic information in speech and that the prosodic exaggeration of IDS supports this ability while children's linguistic and conversational skills are still developing.