The present study compared both linguistic and non-linguistic representations of motion events in Korean–English sequential bilinguals sampled at varying proficiency levels (N = 80) against each other and against those of Korean and English monolinguals (N = 15 each). The bilinguals' L2 descriptions of motion events showed that their encoding patterns were influenced by both the first language (L1) and second language (L2) and also displayed unique behaviors that were not found in either monolingual norm. The non-verbal results on a triads-matching task demonstrated that bilinguals' categorization patterns followed L1-based patterns rather than L2-based patterns. The extent to which these bilinguals employed L2 encoding patterns in their motion event descriptions was largely modulated by L2 proficiency, whereas length of immersion experience in an L2-speaking country emerged as the only predictor of their non-verbal categorization patterns. These findings suggest that the bilinguals' verbal behavior seems more susceptible to change than their non-verbal behavior.
