Proto‑Tai reconstruction of ‘maternal grandmother’ revisited

The word ‘maternal grandmother’ presents irregular modern forms in Tai languages. It is ta:j^B1 in most Northern Tai (NT) varieties, ta:j^A1 in most Central Tai (CT) varieties, na:j^A2 in most Southwestern Tai (SWT) varieties, and ja:j^A2 in Standard Thai. Li (1971) reconstructs the proto-form of this word as *na:j^A , positing that the later forms changed by analogy with semantically similar words. This paper discusses two alternative hypotheses *ta:j^A and *ta:j^B , and argues that the proto-form was *ta:j^B . The analysis indicates that the sound changes of this word in Tai languages are caused by the “contamination” in kinship terms with paired semantic contents in CT/SWT, and by dissimilation from the otherwise homophonous word ‘to die’ in SWT. As a result, the proto-form of ‘maternal grandmother’ *ta:j^B is preserved in the vast majority of NT and a cluster of CT. In most CT/SWT the original *B tone changed to *A tone, and then in SWT the initial *t- underwent further change to *n- in order to avoid homophony with the taboo word ‘to die’. This issue of homophony arose only in this branch due to the merger of *t- and *tr- (or *p.t-). This proto-form *ta:j^B is supported by historical evidence and other non-Tai languages in the Daic family. Other exceptional irregularities in some CT languages are also discussed as they are crucial to the determination of the *ta:j^B hypothesis. Analogous examples from several Tai varieties also support the occurrence of aberrant development due to taboo avoidance.