Rhetorical questions as catalyst in grammaticalization: Deriving Korean discourse marker KETUN from conditional connective

This paper is concerned with a lexical item ketun, which has two functions in Modern Korean: as a conditional connective and as a sentence-terminal discourse marker. The discourse marker is typically found when the speaker clarifies, makes excuses, apologizes, provides background information, mitigates illocutionary forces, or redresses face-threatening acts (FTAs) à la Brown and Levinson, 1987. Despite its apparent direct connection, the character of the functional shift of ketun from a conjunction to a discourse marker is not immediately clear. To date, there is no satisfactory analysis of the grammaticalization processes involved. The chief reason for this seems to lie in the technical difficulty in describing the discourse marker; ketun is represented in a wide range of functional variations. Because of such functional multiplicity, the discourse marker ketun is often described in a diffuse manner, as the ‘explicative’ ketun, the ‘apologetic’ ketun, the ‘redressive’ ketun, the ‘background-laying’ ketun, and the like. The purpose of the present thesis is to provide a principled account of the discourse marker ketun by characterizing it as the ‘authenticative’ marker. This approach allows the essential function of the authenticative discourse marker ketun to be captured and reveals how ketun serves as an effective discourse marker. This paper also shows that the sentence-terminal discourse marker is a direct descendant of the ketun antecedent associated with rhetorical questions, which plays an intriguing catalyst role in the grammaticalization process.