This study investigates how figurative language is processed by learners of a second language (L2). With an experiment testing L2 comprehension of figurative expressions in three categories, each combining shared and unshared first language (L1) and L2 lexical representations and conceptual representations in a different way, the study investigates the effects of L1 conceptual knowledge, L1 linguistic knowledge and L1 frequency. I predict that in cases where the L1 and L2 share similarities in terms of conceptual knowledge (e.g. ANGER IS FIRE) and metaphorical expressions (e.g. "His eyes are burning with anger"), learners will better comprehend the L2 figurative expressions than in cases where the L1 and L2 share no such similarities. I further predict that when L1 and L2 share similarities in both conceptual knowledge and metaphorical expression, L1 frequency will have a positive effect on L2 metaphorical comprehension. These hypotheses are tested by examining the comprehension of advanced-level L2 Korean learners whose native language is English. The testing items are 54 Korean metaphorical expressions related to three emotion concepts (ANGER, HAPPINESS and SADNESS) presented to participants in one decontextualized and two contextualized tasks (limited and elaborated). The results demonstrate that the effects of L1 conceptual/linguistic knowledge and L1 frequency vary depending on the given context. The L2 learners performed significantly better with figurative language for which L1 and L2 show similarities at both lexical and conceptual levels, but only in the conditions of no or limited context. In the same conditions, the study also found a significant effect of L1 frequency on L2 processing of figurative language. This study suggests that the L1 has considerable influence on how L2 metaphorical expressions are processed in a nonsupportive context, even at higher levels of proficiency.