The Discourse Functions and Discourse Environment of Topic

This chapter proposes that the core meaning of topics is derived from the discourse-pragmatic function of defining what a sentence or discourse is about. The primary role of a topic is to establish a domain, signal semantic relatedness for the subsequent comment, and act as a necessary starting point that directs attention toward the focus of the utterance. While often associated with given information or contrast, these are secondary or extended properties rather than the essential defining function of a topic. Topics most naturally consist of activated shared information, though they can also be established through associative or situational activation rather than direct prior mention. Topic particles serve to highlight the topical status of a constituent, particularly when introducing information that has only been indirectly activated or when signaling a topic shift. Contrast is a non-core function reinforced by topic markers to highlight the opposition between different situations or comments revolving around their respective topics. Conditional and hypothetical clauses share formal markers and semantic functions with topics, acting as the background domain for the main clause. Syntactic topicalization, particularly of patient arguments, is significantly more frequent in negative and interrogative contexts as a means of managing discourse focus. The likelihood of a constituent serving as a topic is influenced by factors like animacy and definiteness, where higher animacy or established definiteness facilitates topicalization.