Abstract
Based on the regular correspondence between the Kindaichi tonal classes, originally developed for mainland Japanese dialects, and those of Ryukyuan dialects, this study proposes that the accentual system of proto-Ryukyuan had at most a three-way tonal distinction for words of up to three syllables. Then, assuming that these tonal classes in proto-Ryukyuan can be categorized into at least three large groups, each being supposed to share certain common characteristics in the proto-Ryukyuan accentual system, these are referred to as Pattern Categories (Keiretsu) A, B, and C in this paper. This study then proposes lists of words belonging to each category, based on research conducted on Okinoerabu Island in the Amami region, where the dialect system is known to retain the maximum numbers of tonal distinctions within the Ryukyuan dialect area.
