Exploring the Roles and Pedagogical Functions of Learners' First Language (L1) in Korean as a Foreign Language (KFL) Education: A Systematic Review

This study presents a systematic review of empirical research conducted between 2014 and 2025 on the use of learners’ first language (L1) in Korean as a Foreign Language (KFL) education. A total of six peer-reviewed studies were analyzed following PRISMA guidelines to identify the pedagogical roles, contextual patterns, and instructional implications of L1 use. Findings revealed that learners’ L1 functions across five domains—cognitive, affective, social, metalinguistic, and phonological—and that the scope and intensity of use varied according to learning context and proficiency level. While beginner learners relied on L1 for comprehension and affective reassurance, intermediate learners used it selectively for metalinguistic reflection. Distinctive from English as a Foreign Language (EFL) contexts, KFL studies emphasized phonological support through L1 phonetic transcription and assessment fairness through bilingual test design, reflecting the structural and orthographic characteristics of Korean. The review further indicates a methodological shift from descriptive qualitative approaches to experimental and data-driven frameworks, signaling a growing recognition of L1 as a legitimate pedagogical tool rather than an obstacle to immersion. The study concludes that a strategic and balanced bilingual pedagogy—sensitive to context, proficiency, and instructional goals—offers the most effective integration of L1 in KFL classrooms. Future research should expand to underrepresented populations, including children, heritage learners, and online or AI-supported learning environments, to deepen theoretical and empirical understanding of bilingual mediation in Korean language education.