This paper revisits the longstanding observation that children produce modal verbs (e.g., must, could) with their root meanings (e.g., abilities, obligations) by age 2, typically a year or more earlier than with their epistemic meanings (e.g., inferences). Established explanations for this "Epistemic Gap" argue that epistemic language…

Pierce "et al." (2017) have proposed that variations in the timing, quality and quantity of language input during the earliest stages of development are related to variations in the development of phonological working memory and, in turn, to later language learning outcomes. To examine this hypothesis, three groups of children who are…

This dissertation focuses on when and how children learn about the meanings of the propositional attitude" verbs know" and "think". "Know" and "think" both express belief. But they differ in their veridicality: "think" is non-veridical and can report a false belief; but "know" can only…