The "phase'' alternation in Rotuman is remarkable (and has attracted a good
deal of previous attention) for two reasons. First, the shape differences
between phases are quite diverse, involving resyllabification, deletion, um
laut, and metathesis. Second, the phase alternation produces prosodic struc
tures that are otherwise unattested in this language, replacing simple (C)V
syllables with closed and diphthongal ones. In this article, I argue that
Optimality Theory (Prince and Smolensky 1993) helps to make sense of both t
hese observations. I also go on to use these results to support some claims
about the nature of templates and prosodic circumscription in the theory o
f Prosodic Morphology (McCarthy and Prince 1986).