Using the L1 to disambiguate L2 vocabulary: examining the effects on learning burden and decay with Chinese learners of English

Abstract Word meaning is generally presented to learners via their L1 or the target language. The choice of meaning presentation code may impact the difficulty with which novel vocabulary is learned and how well it is retained over time, yet few studies have considered the effect of meaning presentation code on the learning burden and decay of L2 vocabulary knowledge. Moreover, it is generally assumed that words that are harder to learn are also more easily forgotten. However, there has been minimal investigation of this claim. Addressing these gaps, this paper explores the effect of meaning presentation code on the learning burden and decay of lexical knowledge, and also considers the relationship between burden and decay. Chinese adult learners of English used flashcard software to study vocabulary with meaning presented via L1 equivalents or L2 definitions. Learning burden was operationalised as the frequency of exposure needed to learn target items, and decay was measured by comparing knowledge (form recall and recognition) on immediate and delayed tests. Mixed-effects modelling showed that code did not impact learning burden but did affect decay, with L1 use associated with less decay. Additionally, increased learning burden was associated with greater loss. Pedagogical implications are discussed.