ABSTRACT
The hypothesis of this chapter is that much of the complexity of sentence grammar can be explained as the internalization of features of spoken interaction. Turn-taking, performing speech acts, averring and so on is physically observable as people talk to each other, in dialogue, and it is suggested here that this kind of behaviour provided a series of models for the development of a mode of the language which could sustain long continuous contributions from a single participant. This feature was particularly important in the development of writing.
