This article discusses inflected infinitives in adult first language (L1) Brazilian speakers whose second language (L2) is Spanish. We focus on adjunct clauses headed with para in cases involving same and different subjects in the matrix and the embedded clause. These languages differ in that Brazilian Portuguese, but not Spanish, allows for inflected infinitives, and we provide evidence that these bilinguals are using innovative forms, i.e. inflected infinitives in their L2. We examine our findings under a lens of L1 transfer, L1 pre-emption, and the difficulty posed by the subset–superset relationship between the L1 and the L2. Additionally, we propose that Brazilian Portuguese-speaking L2 learners of Spanish at an initial stage of L2 acquisition encounter challenges abandoning L1 strategies and apply the tense projection’s features in the inflected infinitives of their L1 into the verb forms of their L2. We further propose that those L2 learners with greater vocabulary knowledge succeed in abandoning the L1 strategies that are unavailable in the L2, in contrast to those with a more limited vocabulary knowledge.