Study of Morphophonological Processes in Yoruba Verb Conjugation

Morphophonological processes at the interface of morphology and phonology reveal how a language manages meaning change and phonological well-formedness simultaneously. This study investigates morphophonological processes in Yoruba verb conjugation, focusing on phenomena such as assimilation, elision, and tonal mutation that occur at morpheme boundaries. The research employs a descriptive structural linguistics methodology, drawing data from a corpus of 400 verbal forms elicited from 40 native Yoruba speakers in Oyo and Osun States, South West Nigeria. The study applies optimality theory and lexical phonology to analyse how underlying verb forms are mapped onto surface phonological outputs through systematic morphophonological rules. Existing literature on Yoruba verb morphology has engaged with tone sandhi and elision processes but has rarely applied optimality theoretic constraints to account for variation in verb conjugation patterns. This study fills that analytical gap. The research classifies morphophonological processes by their phonological environment, examining prefix-stem junctures, subject agreement morpheme interactions, and tonal adjustments triggered by aspect and negation marking. The study further investigates dialectal variation in morphophonological processes across Oyo and Ijesa Yoruba varieties. Findings are expected to reveal a set of productive morphophonological rules that are consistent across dialects and a smaller set of variation-prone processes showing dialect-specific behaviour. Recommendations will address the inclusion of morphophonological analysis in undergraduate Yoruba linguistics curricula. Keywords: morphophonology, Yoruba verbs, verb conjugation, optimality theory, tonal mutation.