Reflexes of Middle Korean vowel je in modern dialects and the development of vowel system in Korean

The purpose of this paper is to examine reflexes of Middle Korean vowel je in modern dialects and to discuss the development of the vowel system in this language. In Middle Korean as well as in Modern Korean, the vowel je is peculiar in many ways. First, the diphthong je is different from other diphthongs such as ja, jo and ju in that the latter ones are confined to such word classes as words consisting of Sino-Korean morphemes, onomatopoeia and so on, while the former is not confined to such word classes, and the number of words containing it is much larger than the latter ones. This imbalance shows that the vowel je has a kind of special status that can be comparable to ordinally simple vowels such as a, e, o, u and i. Also, this vowel is peculiar in historical sense. Although this vowel is generally considered to be a central vowel in Middle Korean, there are evidence that it was a front vowel in an earlier stage of this language. This paper tries to reinterpret geolinguistic maps for words containing this vowel and to show that this was indeed the case, thereby proposing possible vowel changes that could have occurred in the vowel system of this language.