The focus of this study is process morphology in Guébie, an endangered Kru language spoken in Côte d'Ivoire. Unlike many primarily affixing morphological systems, much of the morphology in Guébie involves root-internal phonological changes like tone shift and vowel replacement. For this reason, Guébie data have much to offer discussions of the interface between morphology and phonology. Based on the Guébie facts presented here, I argue 1) that process morphology, where a non-concatenative phonological process is the sole exponent of a morpheme, is a subtype of morphologically conditioned phonology, and 2) that not all morphology involves underlying phonological items. I conclude that whether a morpheme triggers a phonological process is independent of whether a morpheme is associated with underlying phonological content. Instead, morphologically conditioned phonological processes are driven by phonological constraints, whose rankings are determined by particular morphosyntactic features present in the domain being phonologically evaluated.

This study describes the phonology and morphology of Guébie, focusing in particular on three case studies of morphologically conditioned phonological processes. These include phonologically determined noun class agreement, scalar tone shift, and vowel replacement. In each of these case studies we see evidence for specific interactions between not only morphology and phonology, but also syntax and phonology. On the morphological side, Guébie tonal morphology shows us that not every morpheme is associated with an underlying (abstract) phonological item. With respect to syntax, we see that domains of phonological evaluation in Guébie must be larger than a single word, but not larger than a syntactic phase. We also see phonological processes sensitive to both morphosyntax and lexical class in Guébie, suggesting that any model of phonological grammar must be able to reference morphosyntactic and lexical information. By exploring morphological exponents across a language, we can narrow down the space of possible models that account for morphosyntactic interaction with phonology.