FROM POLICY TO PRACTICE: EVALUATING THE MEDIUM OF INSTRUCTION FOR EFFECTIVE AND SUSTAINABLE BASIC EDUCATION IN KOGI STATE
The medium of instruction remains one of the most critical determinants of learners' cognitive development, literacy acquisition, and educational achievement, particularly within multilingual societies. In Nigeria, the National Policy on Education prescribes the use of the child's mother tongue or the language of the immediate environment during the first three years of primary education before a gradual transition to English language. Despite this policy provision, implementation across states, including Kogi State, has remained inconsistent due to sociolinguistic diversity, inadequate teacher preparation, insufficient instructional resources, and parental preference for English-medium education. This paper evaluates the extent to which the prescribed language policy has been translated into classroom practice in Kogi State and examines its implications for effective and sustainable basic education. Drawing on policy documents, empirical studies, theoretical literature, and international best practices, the study adopts a qualitative review methodology anchored on language planning and sociocultural theories of learning. Findings indicate a significant disconnect between policy intentions and classroom realities, resulting in reduced learning outcomes, poor literacy development, and widening educational inequalities among learners from different linguistic backgrounds. The study further reveals that effective implementation of mother tongue-based multilingual education has the potential to improve foundational literacy, classroom participation, learner retention, and educational sustainability when supported by adequate teacher training, curriculum development, and community engagement. The paper concludes that strengthening policy implementation requires coordinated efforts among government agencies, educational institutions, teachers, communities, and development partners. It recommends enhanced investment in indigenous language materials, continuous professional development for teachers, improved monitoring mechanisms, and stronger stakeholder advocacy to ensure that language policy contributes meaningfully to quality basic education and sustainable national development in Kogi State and Nigeria at large.