For example, we now all realize that the speaker who says "Its me" is not violating a rule of English by which he should say, "Its I." Rather, the mistake belongs to the grammarian who calls it an error.
Speaker transition without gap or overlap is a feature of the social organization of conversation, achieved always then and there. For example, participants do not retrospectively attain it by editing their memory of a conversation. They do not, in the first instance, go outside the conversation in order to report violations to referees, policemen, oracles, etc., in the hope that external agencies will punish the violators. There is, then, a social organization to turn-taking which has as one of its proper products that one person talks at a time: Achieving this product requires participants to encounter and solve at least two tasks: the collaborative location of transition points, and the collaborative use of means for arriving at who speaks after any current speaker (Beattie, 1983). These are tasks which, on the situated occasions of their solution, are tasks of understanding. And participants so interpret them. They take failing to talk when one has been selected to and another stops as evidence of failing to understand what has been said.
The specific kinds of understanding required for achieving proper turn-taking are determined by how turn-taking is socially organized. For example, if conversation were structured so that the order of speakers and the lengths of their utterances were pre-assigned for whole conversations, turn-taking would impose rather minimal tasks of understanding upon participants (Duncan, 1972). They work in such a way as to require that parties to a conversation do extensive work of understanding if their system of turn-taking is to operate as it does. Both employ utterance units which need to be constantly monitored for their completion. Both operate to select future speakers in an one