The first stage of combinatorial speech is better described as variable than uniform. Talk of variants obscures two different aspects of language (knowledge and use) and two different aspects of language development -- acquisition of the grammar (competence) and deployment of the grammar in speaking and listening (performance). Null subjects and…

In many so-called canonical null subject languages, null and overt subject pronouns have contrasting referential preferences: null subjects tend to maintain reference to the preceding subject while overt pronominal subjects do not. We propose that children acquire this contrast by initially restricting their attention to 1st and 2nd person…

Languages exhibit variation at all linguistic levels, from phonology, to the lexicon, to syntax. Importantly, that variation tends to be (at least partially) conditioned on some aspect of the social or linguistic context. When variation is unconditioned, language learners regularize it -- removing some or all variants, or conditioning variant use…

The phenomenon of regularization -- learners imposing systematicity on inconsistent variation in language input -- is complex. Studies show that children are more likely to regularize than adults, but adults will also regularize under certain circumstances. Exactly why we see the pattern of behaviour that we do is not well understood, however.…

In this paper we investigate the effect of variable input on the acquisition of grammar. More specifically, we examine the acquisition of the third person singular marker -s on the auxiliary "do" in comprehension and production in two groups of children who are exposed to similar varieties of English but that differ with respect to adult…