Evidentiality, the linguistic category which marks the source of the speaker’s information, has often been overlooked in studies of Luchuan (Ryukyuan), the only sister language of Japanese. In this book, Arakaki provides the first comprehensive analysis of Luchuan evidentials. She proposes that Luchuan has a grammatical evidential system which contains one Direct evidential and three indirect evidentials (Inference, Assumed, and Reportative). The discussion includes cross-linguistic issues such as how evidentiality is related to epistemic modality, with the intention that this work should constitute a contribution to the typological and theoretical study of evidentiality. This work will open new horizons for the study of evidentiality.