The Influence of Mother Tongue (Yoruba) on the Acquisition and Proficiency of English as a Second Language among Secondary School Learners in Ogun State, Nigeria

Abstract

This study investigates the pervasive influence of the mother tongue (Yoruba) on the learning and proficiency of English as a Second Language (ESL) among secondary school students in Ogun State, Nigeria. In a multilingual context where English serves as the official language of education and administration, the role of the indigenous language, Yoruba, remains significant in the daily lives of learners. Employing a mixed-methods research design, this study collected data from 300 SS2 students and 15 English language teachers across six secondary schools in the three senatorial districts of Ogun State. Instruments included a proficiency test (covering grammar, lexis, and writing), a questionnaire on language use and attitudes, and semi-structured interviews with teachers. The findings reveal a strong transfer effect from Yoruba to English, manifesting as phonological interference (e.g., vowel conflation, absence of dental fricatives), syntactic interference (e.g., prepositional errors, calquing of Yoruba structures), and lexical interference (direct translation and code-mixing). Quantitative analysis indicates a statistically significant negative correlation (p < .05) between the frequency of Yoruba use in the home and scores on the English proficiency test. Qualitative data from teachers highlight challenges in classroom instruction due to these interferences, despite learners' positive orientation towards English. The study concludes that the mother tongue is not merely a background variable but an active, constraining factor in achieving target-like proficiency in English. It recommends pedagogical strategies such as Contrastive Analysis, increased communicative practice, and teacher training programs that explicitly address language transfer issues to mitigate negative interference and foster a more additive bilingual environment.