The emergence of argument structure from gesture to speech

How does a child of 12 months, who communicates through gestures and proto-words develop into a child of 24 months who says, I ripped the book? Do gestures play a role in children's development of argument structure? These questions are the impetus for the research presented in this dissertation, which brings together two distinct topics in language acquisition: gesture and argument structure. From my data set of 5 children taped weekly from age 12 months to 30 months, I present evidence that children's multi-word utterances develop from early word and gesture combinations in which some elements were earlier expressed through gesture rather than speech.; This dissertation proposes that children are socialized into using culturally significant gestures, such as pointing, and they learn to temporally synchronize these gestures with their utterances. When they do so, caregivers respond to gestures such as pointing, as though they are requests for action, (e.g. look!), while the targets of the gestures are interpreted as being objects (e.g. bottle). Further, when children combine gesture + speech, the two modalities communicate different information. Caregiver response is both more frequent and qualitatively different when children use a single versus multiple modalities.; I propose that caregivers play an important role in the transition from single to multi-word speech when they mediate children's communications through dialogic interaction. I show that caregivers take children's multi-modal word + gesture communications and re-phrase these as word + word communications, modeling the transition from gestures to words. In the final part of the dissertation, I show that gesture plays a role in early word class acquisition. English-learning children's early words are overwhelmingly nouns. Analyzing children's lexical development in light of their gestures may lead to an additional explanation for why young English-learners produce nouns earlier, and with more frequency, than verbs. This multi-modal explanation shows that children's earliest gesture and speech communications are a basis for the later development of argument structure in their multi-word speech.