Cross-linguistically, there are a variety of attested non-phonological conditions onphonotactics and alternations. The extreme end of this are exceptions, whose idiosyncraticbehaviors are unattributable to any morphological, morphosyntactic, or semanticclass. Studying exceptions is challenging because they require a substantive languagedescription to even be identified, and because their identification can appear to subvertdescriptive and analytical generalizations about the grammar. As a result, exceptionalityresearch often focuses on major world languages, and there is considerable contention surroundingwhether exceptions are wholly phonological, extragrammatical, or somethingin between.This dissertation addresses these gaps via an in-depth case study of segmental phonologyin Mushunguli (Somali Chizigula, Kizigua; Narrow Bantu, G.31), an endangered,under-described language spoken by members of the Somali Bantu diaspora. This casestudy, drawn from original fieldwork conducted in 2011-2012, includes a description andanalysis of the hiatus resolution and onset structure conspiracies of Mushunguli, the formerof which exhibits what appear to be four operations (asymmetric coalescence, glideformation, secondary articulation, and elision) in identical morphosyntactic contexts.Situated within this discussion are three exceptional patterns, each representing aseparate typological instantiation of exceptional blocking: a set of high vowel-initial stemsthat exclusively block coalescence, but not other applicable repairs (simple blocking); a prefixand a verb root which unexpectedly undergo otherwise unattested palatalization inlieu of elision (walljumping); and a set of roots that exceptionally block all forms of hiatusresolution (total non-participation). Adopting lexically-indexed constraints in Stratal OptimalityTheory as a means of capturing these patterns reveals complex interdependenciesbetween exceptions and regular forms in Mushunguli, with the form and behavior of oneexception crucially determining the forms and behaviors of other exceptional and regularpatterns. This suggests that exceptions are lexical but not extragrammatical, insteadplaying an important role in the grammar as reifying and reinforcing agents.The study concludes by examining alternative representational analyses of theMushunguli exceptions, including whole-segment absolute neutralization and underspecification.While these approaches are sometimes capable of capturing the exceptionalpatterns, they ultimately struggle to unify or situate them with respect to the grammar asa whole
