The Role of Mother Tongue Instruction in Second Language Acquisition

Abstract

Mother tongue instruction (MTI) has gained renewed attention in second language acquisition (SLA) research due to its significant cognitive, linguistic, and socio-cultural benefits. This article examines the role of learners’ first language (L1) in facilitating effective acquisition of a second language (L2). Drawing upon theoretical frameworks such as the Linguistic Interdependence Hypothesis, Transfer Theory, and Sociocultural Theory, the study argues that strong foundational skills in the mother tongue enhance second language proficiency, academic achievement, and learner motivation. Evidence from bilingual and multilingual education systems indicates that MTI supports conceptual clarity, literacy development, and metalinguistic awareness while reducing cognitive load and educational inequality. The article further discusses pedagogical models, empirical findings, and policy implications, emphasizing that mother tongue instruction should be viewed as a resource rather than a barrier in SLA. The study concludes that integrating MTI into bilingual education frameworks promotes linguistic equity, sustainable learning outcomes, and inclusive education.