This study classified the types of Korean reduplication into phonological reduplication and morphological reduplication, and examined the function of reduplication in word formation according to the type of reduplication.
Morphological reduplication in which language units with meaning is deeply related to the formation of compound words. In particular, in Korean, onomatopoeia, mimicry, and roots overlap a lot. After reduplication, Korean onomatopoeia and mimic words are combined with ‘-hada(하다)’ and ‘-keorida(거리다)’ to form a derivative verb. The stem of an adjective is a compound root form that overlap after change and becomes a derivative adjective, which has the meaning of emphasizing the target state or attribute. On the other hand, phonological reduplication, which is an reduplication of units whose meaning cannot be confirmed, cannot be analyzed any more, so it is related to the formation of a single word. Phonological reduplication is an reduplication of language units that do not have meaning, but it was considered that even units without meaning can express 'repetition' or 'continuity' through reduplication. Phonological reduplication which is related with sensory expression is understood to exert an expressive function that accurately mimics the sound or state of the natural world, and words that show phonological reduplication can be seen as being created as reduplication when words are formed in the first place.