I am interested in how children acquire and develop language, both as monolinguals and bilinguals. Bilingual children hear less of each language than monolinguals do, allowing us to test for effects of input frequency on acquisition. I have often focused on children's acquisition of words and morphology (such as past tense marking). I am also interested in why people produce gestures with their hands while they are speaking: why expend all those calories? Finally, I am interested in how language shapes thought (and vice versa): for example, if someone speaks a language with grammatical gender, does that person start to think of things being male or female?