The purpose of this study is to describe the distributional aspects, meanings, syntactic features of -keyss- shown in the actual Korean spoken language and to research the semantic functions of -keyss- from the perspective of korean language education. It is noticeable that, in the distributional aspects, the idiomatic -keyss- is shown very frequently in the Korean spoken language. To inquiry whether the locutionary aspects of -keyss- are also reflected well in Korean texts for foreigners, it is necessary to examine carefully how the various semantic functions are presented in them. In this study, we describe the problems caused by -keyss- of ‘future’ that is presented first in its semantic functions. And we suggest to present -keyss- used in idiomatic expressions as one unit for more efficient teaching. (Keimyung University)