Chapter 15. A possible grammaticalization in Old Japanese and its implications for the comparison
of Korean and Japanese
Double-negative periphrastic litotes have been for nearly three centuries the usual way to express necessitive predicates in Japanese and Korean. These constructions do not, however, go back to the earliest stages of these languages and should not be invoked as evidence of a possible common origin. But Korean also has a double-affirmative periphrastic necessitive construction. Premodern Japanese has no overt counterpart to it, but it does have an auxiliary adjective that expresses necessity. I argue that this auxiliary was a grammaticalization of a periphrastic analogous in form and meaning to the Korean double-affirmative necessitive, and should be considered as evidence of a common origin. Looking at sampling of Transeurasian languages other than Korean and Japanese, it seems that double-affirmative necessitives may have been an innovation of a branch of Proto-Tungusic that later split into Proto-Korean-Japanese and the predecessor of Manchu.