Abstract

Idioms are frequently used by native speakers but pose challenges for L2 learners. In this study, we aimed to identify the key psycholinguistic properties that predict L2 idiom knowledge among non-immersed speakers. A total of 53 Chilean L2 English speakers participated in an online idiom knowledge test, requiring them to recognize the figurative meanings of 99 English idioms and rate their transparency. The results showed that cross-language similarity and transparency, in conjunction with familiarity, significantly predicted L2 idiom knowledge. Conversely, literal plausibility, decomposability, frequency, and predictability did not significantly impact L2 idiom knowledge. Our findings support the Parasitic Hypothesis of vocabulary development and suggest that non-immersed L2 learners heavily rely on their L1 lexical and conceptual networks. The study underscores the importance of semantic transparency and cross-language similarity in L2 idiom acquisition, particularly for learners in non-immersive environments. Our findings advocate for a proficiency-tailored ESL instruction approach. Initially, focus on teaching transparent idioms and those similar to the learners' native language for better comprehension and retention. As proficiency increases, gradually introduce idioms without cross-language parallels to enhance comprehensive linguistic mastery. This approach offers practical insights for language education and applied linguistics.