According to the Dual Idiom Representation Model (Titone & Connine 1994; Abel 2003), the number of idiom entries created in a learner’s L1/L2 mental lexicon depends on the decomposability and frequency of the idiom and the time of exposure to the language in question. When the idiom is comparatively opaque, the frequency relatively low and/or little time has been spent on acquiring the language, the learner, when trying to interpret idioms, instead resorts to conceptual metaphors that exist across languages. L2 learners also make use of context to a greater extent than L1 speakers. (Liu 2008) L2 idiom comprehension thus appears to entail a more heuristic approach than L1 idiom comprehension. (Liu 2008) In the present investigation 15 first-term university students were faced with 80 context-based idioms in English (L2) and Swedish (L1) respectively (30 of which focused on the source domain of animals which is commonly used in both languages) and asked to explain their meaning. The idioms were of varying frequency and transparency. Three main research questions were thus addressed.

1) How well do the subjects master idioms of approximately the same total frequency in their L2 as compared to in their L1?

2) How do a) degrees of transparency (full transparency, semi-transparency, no transparency), b) idiom frequency and c) the choice of source domain affect the subjects’ comprehension in their L2 as compared to in their L1?

3) To what extent is context used when interpreting the idioms in the subjects’ L2 as compared to in their L1?

The students were also requested to evaluate their knowledge. In addition, native speaker results were used as a point of reference for the L2 test.