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.
Dae-Hyun Jung (Sun,) studied this question.