<jats:p>Although retrieval of lexical forms is a prerequisite for language production, research of L2 vocabulary learning has focused much more on meanings and form-meaning mappings than on development of detailed, accessible mental representations of forms. This is particularly true with respect to multi-word items (MWIs). We report an experimental study involving a variety of intra-lexical, usage-based, and interlingual co-determinants of L2 vocabulary learnability pertaining to MWIs. Each learner (N = 60) encountered a randomly allocated set of 26 two-word MWIs (Nsets = 4) semi-randomly drawn from a larger pool of MWIs. Learners were asked to remember either the 13 MWIs showing the form variable assonance (e.g., <jats:italic>change shape</jats:italic>) or the 13 nonassonant control MWIs (e.g., <jats:italic>sound good</jats:italic>). Posttests of form recall revealed a large, durable effect of the focusing task in combination with forewarning of testing. Except when MWI concreteness (a semantic variable) was high, assonance had a positive effect on retrievability in recall tests given after delays of 15 minutes and one week. There was a consistent effect of the semi-semantic variable Mutual Information. Even in the context of a strong focus on forms, form variables are not the only variables that matter.</jats:p>
They were asked to remember either the 13 MWIs showing the form variable assonance (e.g., change shape) or the 13 nonassonant control MWIs (e.g., sound good).