topic; topic particle

in basic terms, a simple sentence is composed of two elements: the topic or theme (i.e. what is being talked about) and the comment or ‘rheme’ (i.e. what the speaker is saying about the topic). Although this topic–comment dichotomy is generally accepted, the meaning of ‘topic’ in linguistics is difficult to define and a matter of great controversy. In Korean, the topic particle has the basic function of marking something as the (pre-established) topic of conversation.