Aligning the timelines of phonological acquisition and change

This paper examines whether data from a large cross-linguistic corpus of adult and child productions can be used to support an assumed corollary of the Neogrammarian distinction between two types of phonological change. The first type is regular sound change, which is assumed to be incremental and so should show continuity between phonological development and the age-related variation observed in the speech community undergoing the change. The second type is dialect borrowing, which could show an abrupt discontinuity between developmental patterns before and after the socio-historical circumstances that instigate it. We examine the acquisition of two contrasts: the Seoul Korean contrast between lax and aspirated stops which is undergoing regular sound change, and the standard Mandarin contrast between retroflex and dental sibilants which has been borrowed recently into the Sōngyuán dialect. Acquisition of the different contrasts patterns as predicted from the assumed differences between continuous regular sound change and potentially abrupt dialect borrowing. However, there are substantial gaps in our understanding both of the extent of cross-cultural variability in language socialization and of how this might affect the mechanisms of phonological change that must be addressed before we can fully understand the relationship between the time courses of the two.