Pii: S0010-0277(01)00172-x

There are currently two theories about how children acquire a language. The first is generative grammar, according to which all human children innately possess a universal grammar, abstract enough to structure any language of the world. Acquisition then consists of two processes: (1) acquiring all the words, idioms, and quirky constructions of the particular language being learned (by ‘normal’ processes of learning); and (2) linking the particular language being learned to the abstract universal grammar. Because it is innate, universal grammar does not develop ontogenetically but is the same throughout the lifespan – this is the so-called continuity assumption (Pinker, 1984). This assumption allows generativists to use adult-like formal grammars to describe children’s language and so to assume that the first time a child utters, for example, “I wanna play”, she has an adult-like understanding of infinitival complement sentences and so can generate ‘similar’ infinitival complement sentences ad infinitum. Tomasello (2000) reviewed a number of observational and experimental studies which show – contrary to the continuity assumption – that children are not very productive with their early language, suggesting that they do not possess the abstract linguistic categories and schemas necessary to effortlessly generate infinite numbers of grammatical sentences. He also pointed out that there are no satisfactory explanations in the current literature of how a child might possibly link an abstract universal grammar, if there were such a thing, to the particularities of the specific language being learned (the linking problem). The second theory, one version of which was sketched in the final part of Tomasello (2000), simply does away with universal grammar and the theoretical problem of how a child links it to a particular language. The approach advocated is based on theories in Cognitive-Functional (usage-based) Linguistics (e.g. Bybee, 1985, 1995; Croft, 2000, in press; Goldberg, 1995; Langacker, 1987, 1991), and so it is a single process theory. Children acquire the more regular and rule-based constructions of a language in the same way they acquire the more arbitrary and idiosyncratic constructions: they learn them. And, as in the learning of all complex cognitive activities, their initial learning is M. Tomasello, K. Abbot-Smith / Cognition 83 (2002) 207–214 207