ASPECTS OF OLUKUMI PHONOLOGY
Olukumi is a Yoruboid language spoken by the Ukwunzu and Ugbodu people of Delta state, Nigeria. Hitherto the study, Arokoyo (2012) superficially described the sound system of the language in comparative study of four Yoruba group of languages. Her analysis however did not account for certain vital aspects of the phonology of the Olukumi language. As such, this study sets out to study those aspects of the phonology of the language that were not adequately accounted for. This research work provides an adequate description of the sound system of the language including tone and syllable structure. It also highlights and describes those assimilatory processes that are evident in the language. Furthermore the study provides adequate description of those processes that affects the syllable structure of the language. Since syllable structure processes converts or deletes tone bearing units (TBUs), the study also highlights some of the tonal processes that take place when TBUs are deleted in the language. Data for this study were collected primarily by means of oral interview of four indigenes of Ukwunzu who have native competence in Olukumi. The Ibadan four hundred word list and a self constructed word list were used to gather primary data from the four respondents. The minimal pair test was used to identify distinctive consonants, vowels and tones in the language. The Sound Pattern of English (SPE)framework propounded by Chomsky and Halle (1965) was used for the analysis of assimilation and syllable structure processes. However, since the SPEframework is not capable of handling non-linear/suprasegmental features, the Autosegmental framework propounded by Goldsmith (1976) was adopted for the analysis of tone and other suprasegmental features. This research shows that contrary to earlier claims, the Olukumi language has twenty-four consonants, nine oral and five nasal vowels, three possible syllable types (two basic syllable V, CV and a third phonological syllable CGV), and rtwo basic tones. Some of the prevalent phonological processes includes: palatalisation, labialisation, nasalisation, nasal spread, nasal stability, vowel harmony, vowel harmony spread, vowel deletion, vowel insertion, consonant deletion and glide formation. Some tonal processes that are prevalent in the language includes: tone deletion, tone stability and tone mobility. Contour tone in this language is a concatenation of the Low and High tone which merge as a result of tone stability. Given that phonology is one of the basic areas of linguistic description, this study serves as a foundation for further research into such areas like syntax, lexicography, morphology documentation and so on.