This paper examines the sequential nature of the functions of lexical items, discourse markers and speech formulae. They signal relations between units of talk by virtue of their sequential position as initial or terminal brackets demarcating discourse units. Speakers of natural language have a large number of detailed expectations about how a particular routine sequence might run. Turn beginnings and turn endings are especially important since they display relevance to what has preceded and provide projections and connections for following turns. It is argued that turn-initial and turn-final markers have evolved, in response to divergent interactive forces within an ongoing discourse, a number of sharply distinct discourse functions. While the use of initial markers is connected with turn entries, turn transitions or receipt of information, the use of final markers is linked with epistemic and affective stance. Epistemic and affective stance has an especially privileged role in the constitution of social life, which accounts in part for why stance is elaborately encoded in the grammar of Chinese.