Parallelisms in the Verb Morphology of Sidaba rGyalrong and Lavrung in rGyalrongic

An impressive variety of divergent yet closely related forms of Qiangic (Tibeto-Burman) are spoken by the rGyalrong Tibetans in northwestern Sichuan, for which a distinct linguistic group rGyalrongic is proposed herein, consisting probably of three major languages: rGyalrong proper, Lavrung, and Horpa-Shangzhai. This paper explores, on the basis of fresh first-hand data, possible close affinities between a particular pair in rGyalrongic: Sidaba rGyalrong (represented by the Caodeng dialect) and Lavrung (represented by the Mu’erzong dialect). Three peculiar parallelisms in inflexional verb morphology between Sidaba rGyalrong and Lavrung are examined: (i) glottality-inversion in past-stem formation, (ii) ablaut, (iii) transitivity marking via vocalic alternation in the orientation prefixes. These striking morphological agreements, whether indicating archaisms or innovations, will be important facts to consider in subgrouping rGyalrongic as well as in reconstructing its proto-morphosyntax.