A Systematic Framework for Error-Based Instructional Strategies in Korean Language Education: A Case Analysis of Vietnamese Learners' Grammatical Errors

This study reconceptualizes learner errors as pedagogically valuable evidence of the cognitive and structural gaps between Vietnamese and Korean, rather than temporary deviations to be eliminated. It aims to build a systematic, theory-anchored instructional strategy for Korean language education grounded in those errors. A corpus of 900 error sentences produced by Vietnamese learners—sourced from writing tasks, spoken transcripts, and prior studies—was coded along four dimensions: error type (ec-), error cause (cause-), instructional strategy (strategy-), and pedagogical theory (theory-). The multi-layered coding linked each error to an instructional response aligned with six established theories: Focus on Form, Noticing Hypothesis, Skill Acquisition Theory, Sociocultural Theory, the Presentation-Practice-Production model, and Input Processing Theory. Expert validation confirmed both reliability (Cohen’s κ = 0.87) and content validity (CVI = 0.89). Results show that postposition omission, tense mismatch, honorific misuse, and verb-order errors recur most frequently, reflecting Vietnamese syntactic transfer. Matched strategies—including structured input, consciousness-raising tasks, and guided interaction—displayed high theoretical coherence and classroom feasibility in expert ratings. By treating errors as diagnostic windows into interlanguage development, this study offers a replicable framework for error-based instruction that integrates contrastive analysis with cognitive and sociocultural perspectives. The model equips Korean language educators with targeted, empirically grounded techniques and suggests a transferable approach for multilingual contexts where native-language influence is pronounced.