When do children map clause types to canonical speech acts?

Abstract

The clause types of declarative and interrogative map to the different speech act functions of asserting and questioning, respectively. Declaratives and interrogatives also consistently differ in their prosody and syntactic organization. Specifically, polar interrogatives are formed through subject–auxiliary inversion, whereas wh-interrogatives are formed with the corresponding wh-word. We are interested in infants’ understanding of these clause types and speech acts, as well as how they develop their knowledge of them. A previous study we conducted found that 18 month olds can link polar interrogatives to an uninformed speaker. Building on this finding, we are conducting a study testing the polar interrogative knowledge with 15 month olds, as well as a new dimension: whether 18 month olds can link wh-interrogatives to an uninformed speaker. In this study, we show infants videos featuring two bears with differing levels of knowledge about an object in a box, prompting an informative exchange.