Investigating the harmonic variations of high vowels patterns across Yoruba dialects: a correspondence approach

This study examines Advanced Tongue Root (ATR) harmony of high vowels [i] and [u] in three Yoruba dialects: Standard Yoruba (SY), Ife Yoruba (IY), and Ekiti Yoruba (EY). Previous analyses, such as alignment-based approach in Grounded Phonology and Optimality Theory (Archangeli & Pulleyblank, 1989, 1994), provide directionality rules for vowel harmony but struggle to account for dialectal differences. Orie (2003) proposes a dual-framework model that combines alignment with prosodic licensing to account for these variations. However, this approach introduces theoretical redundancies and assumes the prosodic head status of the final vowel despite the lack of independent evidence supporting this. To offer a more streamlined explanation, this research adopts Krämer (2003) Correspondence Approach, which emphasises feature preservation through constraints like R-ANCHOR and S-IDENT(ATR) alongside markedness constraints such as *[+high, -ATR]. Though effective, Krämer's framework is not without its limitations, such as its reliance on local conjunction of constraints introduces unnecessary complexity. This study refines his model by replacing local conjunction with new markedness constraints such as *[+high, -ATRright(root)], enhancing both the clarity and generalizability of the analysis. With the underlying assumption that only [-ATR] is specified and directly associated with all vowels in the input, the findings of this study reveal that the interaction between faithfulness and markedness constraints varies across the dialects. In Ekiti, faithfulness constraints dominate initial and medial root positions, preserving the retracted [-ATR] feature of high vowels despite markedness violations. Conversely, SY and IY prioritize markedness, realizing high vowels as [+ATR] in similar positions to avoid retracted high vowels. However, all three dialects converge in final root positions, where markedness constraints like *[+high, -ATRright(root)] override faithfulness constraints, ensuring final high vowels surface as [+ATR]. Through the Correspondence Theory, this study offers a cohesive explanation for ATR harmony in Yoruba dialects, contributing to broader phonological theories of vowel harmony in African languages.