This paper analyzes the problem of grammatical regulations on suffixes related to modality, mood, and tense in contemporary Korean and exemplifies a number of ungrammatical suffix usages that are still used as appropriate expressions in conversational interactions. I emphasize that the resolution of these problems require the studies of these suffixes from the perspective of a cognitive-pragmatic approach, and not through the rules of formal linguistic regulation. I assert that the choice of a speaker`s stance should be a basis for expounding the system of linguistic usage involved with modality, mood, aspect, and the speaker`s manner. This paper illustrates how the categories of modal logic can be differentiated into a variety of lexical, semantical, and syntactical forms in contemporary Korean.
