Editing Topic and comment (section)

{{Short description|Terms describing sentence structure in linguistics}}
{{About|the topic of a sentence|the topic of a discourse|Discourse topic|theme (also called topic) in generative grammar|Theta role|theme in semantics|Thematic relation}}
{{More citations needed|date=October 2011}}
{{Use dmy dates|date=June 2015}}
{{Grammatical categories}}

In [[linguistics]], the '''topic''', or '''theme''', of a [[Sentence (linguistics)|sentence]] is what is being talked about, and the '''comment''' ('''rheme''' or '''[[Focus (linguistics)|focus]]''') is what is being said about the topic. This division into old vs. new content is called [[information structure]]. It is generally agreed that [[clause]]s are divided into topic vs. comment, but in certain cases the boundary between them depends on which specific [[grammatical theory]] is being used to analyze the sentence.

The topic of a sentence is distinct from the grammatical [[Subject (grammar)|subject]].  The topic is defined by [[Pragmatics|pragmatic]] considerations, that is, the [[wiktionary:context|context]] that provides meaning. The grammatical subject is defined by [[Syntax (logic)|syntax]]. In any given sentence the topic and grammatical subject may be the same, but they need not be. For example, in the sentence "As for the little girl, the dog bit her", the subject is "the dog" but the topic is "the little girl".

Topic being what is being talked about and the [[Subject–object–verb word order|subject]] being what is doing the action can, also, be distinct concepts from the concept [[Agent (grammar)|agent]] (or actor)—the "doer", which is defined by [[semantics]], that is, by the contextual meaning of the sentence in the paragraph. In English clauses with a [[verb]] in the [[passive voice]], for instance, the topic is typically the subject, while the agent may be omitted or may follow the preposition ''by''. For example, in the sentence "The little girl was bitten by the dog", "the little girl" is the subject and the topic, but "the dog" is the agent.

In some languages, word order and other [[Syntax|syntactic phenomena]] are determined largely by the topic–comment (theme–rheme) structure. These languages are sometimes referred to as [[topic-prominent language]]s. Korean and Japanese are often given as examples of this.