A voicing rule for non-continuant obstruents in Thebo Tibetan

Abstract Voicing alternation and the function of Tibetan verbal prefixes are two problems that have attracted scholars of Tibetan and Sino-Tibetan linguistics for over a century. This article presents a voicing rule in Thebo Tibetan and systematically analyzes the verb paradigm to explain the constraints for this rule and its apparent exceptions. The latter part of this article analyzes the evolution of the verbal paradigm from Old Tibetan to Thebo, using a model based on exceptions, sound laws, and analogy, and proposes the derived direction of the irregular verbal alternations in Thebo. The main contribution of this study is to provide additional evidence in solving the enigma of directionality for voicing alternation in Tibetan.