Proto-Korean-Japanese: A New Reconstruction of the Common Origin of the Japanese and Korean Languages

Even after more than a century of linguistic research, the question of whether the Japanese and Korean languages share a common origin remains unanswered. This dissertation presents evidence for a comprehensive theory that Japanese and Korean descend from the same ancestor language, 'proto Korean Japanese'. I employ the Comparative Method of historical linguistics (Campbell 1999, Hock & Joseph, 1996) to propose over 500 Korean Japanese related words that build on the foundations laid by Martin (1966) and Whitman (1985). I also offer original theories of how the Japanese and Korean grammatical systems can be traced back to a common proto Korean Japanese grammar, and explain how such grammatical correspondences are unlikely to be the result of borrowing or chance. This means that related words and grammatical structures can only be explained as inheritances from the same source language. Finally, I discuss how the most reasonable interpretations of non linguistic evidence from Korean and Japanese history also point to common linguistic ancestry. Crucially, this dissertation is able to identify a significantly greater number of shared Korean Japanese words than previous research such as Martin (1966) or Whitman (1985), who have previously underestimated the amount of shift in grammar and meaning that has taken place in both languages. This dissertation thus establishes a strong set of core correspondences in the vocabulary of Japanese to that of Korean, and provides a solid basis for positing common origin for these two languages.