First language development: a usage-based perspective on past and current research.

I first outline three major developments in child language research over the past forty years: the use of computational modelling to reveal the structure of information in the input; the focus on quantifying productivity and abstraction; and developments in the explanation of systematic errors. Next, I turn to what I consider to be major outstanding issues: how the network of constructions builds up and the relationship between social and cognitive development and language learning. Finally, I briefly consider a number of other areas of importance to a psychologically realistic understanding of children's language development.