In the era of communicative language teaching, analyses of teacher talk typically focus on the characteristics that make, or fail to make such talk ‘communicative’. In most cases, the criteria for communicativeness are taken from what is felt to constitute communicative behaviour in the world outside the classroom. Thus, communicative classroom are held to be those in which features of genuine communication are evident, and, by exclusion, classes where they are not present are considered to be uncommunicative. In the case of teacher talk, similar criteria might be used to assess such aspects of classroom language use as the kind of questions teachers ask their students, or the way they respond to student contributions. In this article, I argue that this analysis of teacher talk is over-simplistic, and ultimately unhelpful to teachers since its attempt to characterize communicativeness only in terms of features of authentic communication which pertain outside the classroom ignores the reality of the classroom context and the features which make for effective communication within that context