Published online by Cambridge University Press: 01 January 2026
Current theories of optionality often take a gradient view of grammaticality: unattested variants are not categorically excluded but rather highly improbable. Vowel harmony in Eastern Andalusian challenges this view. Unstressed vowels optionally harmonize in a coordinated fashion. For example, if one posttonic vowel harmonizes, they all must. Different implementations of NOISY HARMONIC GRAMMAR are tested for their ability to account for this pattern. Only the implementation that categorically excludes forms with uncoordinated harmony succeeds; other implementations, which can only make such forms unlikely outputs, provide inferior models. This contrast indicates that there remains a need for a categorical approach to (un)grammaticality alongside a gradient approach.
For feedback on this work, I wish to thank Rachel Walker, participants in the Analyzing Typological Structure workshop at Stanford University, and audiences at Linguistics at Santa Cruz 2020 and the 16th Old World Conference in Phonology. I am especially grateful to Bruce Hayes for his generous efforts to ensure that my simulations functioned properly in OTSoft.