Conceptual and prosodic cues in child-directed speech can help children learn the meaning of disjunction

At first glance, children’s word learning appears to be mostly a problem of learning words like dog and run. However, it is small words like and and or that enable the construction of complex combinatorial language. How do children learn the meaning of these function words? Using transcripts of parentchild interactions, we investigate the cues in child-directed speech that can inform the interpretation and acquisition of the connective or, which has a particularly challenging semantics. Study 1 finds that, despite its low overall frequency, children use or at adult levels by age 4 in some speech acts. Study 2 uses annotations of a subset of parent-child interactions to show that disjunctions in child-directed speech are accompanied by reliable cues to the correct interpretation (exclusive vs. inclusive). We present a decision-tree model that learns from a handful of annotated examples to correctly predict the interpretation of a disjunction. These studies suggest that conceptual and prosodic cues in child-directed speech can provide information for the acquisition of functional categories like disjunction.