Establishing relative chronology of Palaung sound changes using Tai loanwords

The sequence in which different sound changes occur in a language can be
established by identifying feeding/bleeding relationship among the changes. In
many cases, however, it is not possible to establish the relative chronology
among certain changes because they are not in either feeding or bleeding
relationships. The chronology of changes from Proto-Palaung to the Red
Palaung presents such a problem. While there is clear evidence for voicing
flip-flop and vowel shift, the sequence in which the changes occur is not
recoverable from Paluang-internal evidence. Fortunately, Red Palaung has a
large number of Tai loanwords, some of which reflect earlier stages of the Shan
language. Because a set of loanwords may have been incorporated into Red
Palaung before one change but after another, conclusions about the relative
chronology among those sound changes can be drawn by applying the principle
of feeding/bleeding relationships to those Tai loanwords. In this paper, I argue
that Tai loanwords indicate two different series of vowel shifts in Red Palaung
intervened by the voicing flip-flop. Moreover, I use these Tai loanwords to
locate the three sound changes chronologically with reference, and provide
tentative dates for the PR sound changes.