Formulaic language in L1 acquisition

The recognition that speech formulas play a role in first language acquisition-that children reuse sequences of words taken directly and seemingly unanalyzed from the input-goes back to the earliest days of the field. Until fairly recently, however, such formulaic language was considered part of an early and soon-superseded stage of development. The last decade has seen the rise of a perspective on language development in which such formulas are central to language acquisition across development. According to this perspective, which is often known as the usage-based theory of language development, acquisition begins when children identify, infer a communicative function for, and start to utilize pieces of language of different sizes (single words and multiword sequences). Generalization, and as a result grammar, is an emergent property resulting from the ongoing coexistence of such sequences in a shared representational space. The growth in popularity of such an account, which represents a radical break from traditional models of grammatical development, has resulted in large part from the appearance of very large corpora of child-caregiver interactions. Such corpora have supported a new understanding of the challenges and opportunities facing the learner, as well as allowing new naturalistic analyses of children's productions and the creation of stimuli for experiments, all of which offer considerable support for the usage-based position. This article offers a review of these developments.