Abstract
I propose that Mandarin 。-sentences (units marked by 。) are aspectual topic-comment sequences, where an initial update (terminating in a pause) introduces a topic state for comment by one or more clauses. Each comment anaphorically refers to the topic state via the aspect feature of the verbal predicate. This proposal explains why Mandarin 。-sentences have controversial boundaries, since speakers may disagree where one topic state ends and the next one begins. It also explains various manifestations of aspect-prominence and topic-prominence in Mandarin discourse. In Bittner (2014), this proposal is formally implemented in Categorial Grammar and a new dynamic logic called Update with Centering.