Constraint reranking in diachronic OT: binary-feet and word-minimum phenomena in Austronesian

Abstract Languages throughout the Malayo-Polynesian branch of Austronesian exhibit a range of sound changes which all appear to be triggered by the presence of a schwa in an open penultimate syllable. These changes are gemination of the final-syllable onset, deletion of penultimate schwa in three-or-more syllable words, and the shift of schwa to a full vowel in open penultimate syllables only. The changes are analyzed as a product of drift, whereby changes in daughter languages are motivated by some property of the proto-language. In this case, it is argued that schwa was a zero-mora vowel in Proto-Austronesian and Proto-Malayo-Polynesian, and that these changes worked to add a mora to a word which would otherwise contain a degenerate single-mora foot. The observed changes are then analyzed as a product of constraint promotion modeled in Diachronic Optimality Theory, whereby constraint movement over time may explain historical sound change. In the case of Malayo-Polynesian, it is shown that the promotion of the Binary Foot constraint ( Ft-Bin) can explain all three of the attested schwa-triggered sound changes.