Exposure to English is more extensive in today’s society than to French. In this study we investigated crosslinguistic influences from Dutch and/or English to language performances in French as a foreign language, while controlling for language proficiency in French, English and Dutch, and exposure to English. We tested Dutch learners of French (n = 65) with respect to the acceptability of reduced relative clauses and attachment preferences in full relative clauses. The results showed crosslinguistic influence in the acceptability task and the preference task from English and Dutch respectively. Furthermore, language proficiency in English seems to affect attachment preferences in French. We concluded that these findings support the Linguistic Proximity Model (Westergaard et al. 2017) and that French in Dutch secondary education might be a third language, instead of a second language.