The role of receptive vocabulary knowledge in spoken and written production of second language Korean

Abstract

This study examines the extent to which receptive vocabulary size supports productive language performance among second language (L2) Korean learners. While vocabulary knowledge has been established as a key component of language proficiency, its specific contribution to speaking and writing remains understudied in the context of Korean as a second language (KSL). Drawing on the Complexity, Accuracy, and Fluency (CAF) framework, this study investigates how learners’ receptive vocabulary knowledge relates to productive performance.A total of 119 L2 Korean learners completed the Korean Vocabulary Levels Test (KVLT) and performed three speaking and three writing tasks. Quantitative analyses revealed that vocabulary size was most strongly correlated with fluency in both modalities, while association with accuracy was weaker. Task effects were also observed: The Opinion-Based task elicited more fluent and lexically rich output in the speaking modality, whereas the Descriptive task elicited more fluent and syntactically complex output in the writing modality. These findings suggest that receptive vocabulary knowledge enhances language production across both modalities, with some variation. This study highlights the role of lexical knowledge in supporting L2 Korean production and emphasizes the importance of incorporating vocabulary instruction into curriculum design, alongside careful consideration of task type and modality. The findings underscore the need to reconsider the role of vocabulary teaching in enhancing L2 Korean learners’ productive language skills (speaking and writing), offering key pedagogical implications for fostering balanced development in Complexity, Accuracy, and Fluency (CAF).