日本語の方言
Early reconstructions of the proto-language, culminating in the work of Samuel Martin, were based primarily on internal reconstruction from Old Japanese. Evidence from Japanese dialects and Ryukyuan languages was also used, especially regarding the history of the Japanese pitch accent, but otherwise assuming a secondary role. The complementary approach of comparative reconstruction from the dialects and Ryukyuan has grown in importance since the work of Shirō Hattori in the 1970s.