Many studies have shown that the transfer of receptive L2 vocabulary into production is far from linear, whether production is elicited by a task or spontaneous. The nature and causes of this gap between receptive and productive vocabulary knowledge have been widely debated. This article attempts a novel approach to this topic by investigating vocabulary knowledge development in a detailed case study. Four knowledge levels of ESL vocabulary are traced across time during a 36-week period of intensive exposure to the target language. Detailed analyses reveal that these knowledge levels interact in a complex way over time, simultaneously competing for learner resources and conditionally supporting each other's growth. A model based on dynamic growth equations supports the hypothesis that complex interactions between vocabulary knowledge levels give rise to the receptive-productive gap.
vocabulary development
