The complexity and history of verb-stem ablauting patterns in Siyuewu Khroskyabs

This paper describes the ablauting patterns in Siyuewu Khroskyabs, an understudied Gyalrongic language. Ablaut is only found in verbs containing closed syllables, and ablaut patterns in Siyuewu preserve Proto-Khroskyabs patterns relatively well. After providing a synchronic description of verb-stem functions and ablauting patterns, implicative entropy is used to model Siyuewu’s ablauting status. Entropy measurements reveal Siyuewu to have relatively low ablaut predictability, which may be suggestive of a historically conservative ablauting system. On the basis of this quantitative analysis, the current paper proposes an internal reconstruction of ablauting patterns, and postulates a series of velarised vowels for Proto-Siyuewu. Analogical changes are identified through comparison with other Gyalrongic languages. The reconstructed verb forms and patterns are then compared with neighbouring Gyalrongic languages and the directionality of analogy is discussed.