On the Nature of Proto-Oceanic *o in Southern Vanuatu (and Beyond)

The languages of Southern Vanuatu are unusual among Oceanic languages in that the default reflex of Proto-Oceanic *o is front or central and unrounded, and not back and rounded. Loan phonology also suggests that /o/ was a fairly late development in Southern Vanuatu languages. While front vowels condition "palatalization" of *t in all Southern Vanuatu languages (and of *l in some), *o also conditions palatalization in some words (though not in others). Similar but not identical developments occur in some North Central Vanuatu languages and in the Western Oceanic language Mbula. This leads into an attempt to redefine the vowel system of Proto-Oceanic, suggesting that it was not in fact the five-vowel system /*i *e *a *o *u/ currently accepted. The latter is the system that emerged in various branches after the breakup of Proto-Oceanic. The evidence indicates that Proto-Oceanic itself retained Proto-Malayo-Polynesian *ə. Depending on the chronology of the changes Proto-Malayo-Polynesian *ay > Proto-Oceanic *e and Proto-Malayo-Polynesian *aw > Proto-Oceanic *o, the Proto-Oceanic system was probably one of /*i *ə *a *o *u/, /*i *e *ə *a *u/, or / *i *e *ə *a *o *u/.