The main purpose of this study is to observe the L2 acquisition effect of studying abroad during approximately four months in Swedish non-native speakers (NNSs) of Spanish with respect to their use of multi-word structures (MWSs) as compared to native speakers (NSs). In addition, this evolutionary study has a secondary aim which is to see the effect of the activity type on the amount and distribution of the MWSs encountered.    This study shows positive effects of a study abroad period in L2 use and, particularly, regarding MWSs. It has been shown that the amount and variety of the NNSs’ MWSs have increased during their stay in Spain, and that the differences with the NSs in the use of MWSs have diminished or even, in some cases, disappeared. It is notable the improvement in the NNSs’ discourse competence. The study also shows that the type of task affects the results. Thus, the negotiations that contain specialised vocabulary which participants are familiar with, yield a higher token frequency of MWSs among NSs and NNSs than the focus group discussions, more free and spontaneous. The negotiations also yield a higher token frequency of conceptual MWSs, especially noun phrases, because of the specialised vocabulary, more complex and subject to greater nominalisation.The focus group discussions have a higher token frequency of own-management MWSs than the negotiations, which is attributed to a higher communicative pressure. On the other hand, the token frequency of interaction management MWSs is higher among the NSs in the mixed group discussions compared to those with only NSs, as a result of collaborative interaction between the NSs and the NNSs. Individual differences among NNSs have also been observed and five profiles have been distinguished. These differences decrease in general at the end of the stay, which also indicates a positive development. There is a positive development in all profiles, which is reflected in significant changes in the amount and variety of the MWSs, their distribution in categories or in the emergence of more complex types. A direct link has also been observed between communication orientedness, participation in conversation and a positive development.