This study presents a comprehensive analysis of assimilation processes in the Tiv language, employing generative phonology theory (Chomsky & Halle, 1968). Tiv, a Southern Bantoid language spoken by over 5.2 million speakers, exhibits systematic phonological processes that have received limited formal analysis.

Through examination of naturally occurring speech data from the Gboko and Masev dialects, this research identifies three primary types of assimilation: progressive, regressive, and coalescent.

Progressive assimilation predominantly involves /e/ influencing / a/, particularly in the Gboko dialect. Regressive assimilation, more prominent in the Masev dialect, demonstrates opposite directionality

with /a/ influencing preceding /e/. Coalescent assimilation, widespread across general Tiv, involves vowel merger, particularly /a/ + /u/ → [ôô] and /e/ + /u/ → [oo].

Using formal rule notation,

the study establishes systematic patterns governing these processes, contributing to Tiv phonology documentation and broader phonological theory. The findings have implications for language

pedagogy, orthographic development, and comparative Niger-Congo linguistics.