CODE-SWITCHING AND CODE-MIXING IN NIGERIAN UNIVERSITIES: A STUDY OF UNIVERSITY OF DELTA, AGBOR, DELTA STATE, NIGERIA

English has become the most widely spoken language globally, making it indispensable for effective international communication (Crystal, 2003). Consequently, individuals aiming to succeed in the contemporary global society must attain a high level of proficiency in English (Kachru, 2006). This study investigates the influence of code switching (CS) and code mixing (CM) on the learning of the English language in Nigerian universities, using the University of Delta, Agbor, as a case study. The objectives of the study were threefold: (1) to identify the reasons for the prevalence of code switching and code mixing in Nigerian university classrooms; (2) to assess how CS and CM affect students’ academic performance in learning English; and (3) to propose effective strategies for minimizing the use of CS and CM in English language instruction (Bamgbose, 1991; Akindele & Adegbite, 2005). The study was anchored on the Matrix Language Frame theory and the Sequential Theory, both of which provide frameworks for understanding language alternation patterns in multilingual settings (Myers-Scotton, 1993; Gumperz, 1982). A descriptive research design was employed, and the study utilized a mixed-methods approach for data collection, analysis, and interpretation (Creswell, 2014). The research population consisted of 100 students from the University of Delta, Agbor, and the entire population was selected using a simple random sampling technique. Primary data were gathered using questionnaires, interview guides, and observation checklists, while secondary data were obtained through documentation and literature review. Findings from the study revealed that the primary reasons for the use of CS and CM include limited vocabulary, the need to emphasize specific concepts during instruction, and the intention to clarify meaning (Ayeomoni, 2006; Yusuf, 2015). Moreover, the study showed that frequent use of CS and CM negatively impacts students’ proficiency in English by diminishing their confidence in speaking, limiting opportunities for language practice, hindering language mastery, and reducing overall comprehension (Ihemere, 2006; Igboanusi, 2002). Notably, it was also found that instructors are the main facilitators of CS and CM in the classroom environment. Based on these findings, the study recommends that school administrators and English language educators should reinforce policies mandating the use of English on school premises and ensure strict compliance through active monitoring (Ogunniyi, 2011). Teachers should model proper English usage by refraining from code switching and code mixing during instruction. Additionally, education policymakers are urged to introduce short-term professional development programs focused on curbing CS and CM among teachers to enhance students’ acquisition of the English language (Fakeye, 2010).