It is argued that the reduplication of Jeju Korean is a case of cooperation of universal grammar of perception and localized grammar of production. While the general shape of emphatic forms is made through maximizing the perceptual distance such as Maximize Distance of Formants, Maximize Distance of Duration, and Maximize Distance of F0, the specific arrangement of the perceptual principles is applied by phonotactic grammars which are realized as raising and fronting in vowels as well as tensification, aspiration, and onset or coda addition in consonants. This process of negotiation between two grammars is a motivation of the reduplicative adverbs.