This paper deals with questions involving the polysemous meanings of Korean delimiter to, which include existence of a sister item, polar values, emphasis, reciprocality, and concession among others. In this paper it is argued that the basic meaning of to is the implication of a sister proposition and that various other meanings can be pragmatically derived from the basic meaning. The pragmatic notion of emphasis is defined formally and it is shown that various meanings of to can be accounted for by investigating how the speaker exploits the background knowledge which the speaker and the listener share in a speech context. According to what type of the context is made use of by the speaker, the various polysemous meanings are analyzed as involving either a simple implicature or a series of implicatures, i.e., scalar implicatures, so the various meanings of the delimiter can be attributable to the different attunement of the speaker to different kinds of context.