Chapter 8. Old Japanese bigrade paradigms and Korean passives and causatives
There is a consensus that two Old Japanese (OJ, 8th c. ce) verb paradigms, called <i>bigrade</i>, were not present in proto-Japanese (pJ, 1st millennium BCE). There is less agreement on how the bigrades originated and how many unitary pJ vowels their reconstruction requires. I argue here that bigrade verbs began as a proto-Korean-Japanese (pKJ) passive or inchoative formation, and that six unitary pJ vowels (allowing intrasyllabic glides) suffice to capture the observed alternations of bigrade and all other verb stems. An alleged seventh pJ vowel, *ɨ, is not needed, though it may have been present in proto-Korean-Japanese. The pKJ reconstructed passive may have been an innovation that distinguished it from other Macro-Tungusic branches.