Several studies have demonstrated that Dutch has a stronger tendency towards compounding than French (e.g., Du. zoutwaterzwembad vs Fr. piscine d’eau salée ‘saltwater pool’) (Van Goethem 2009; Van Goethem & Amiot 2019), especially when adopting a restrictive approach of compounding in which the presence of prepositions and/or internal inflection in multi-word expressions is considered evidence for their syntactic formation (Fradin 2009). The example above illustrates that Dutch compounding differs from French in another important aspect: while Germanic compounding is by definition right-headed, French has a general tendency towards left-hand headed compounds and phrases. Nevertheless, little attention has been paid so far to the impact of such cross-linguistic differences on the use of compounds in learner language, even though word-formation awareness has been proven crucial for learners’ proficiency and creativity (Balteiro 2011). In this presentation, we investigate the impact of these cross-linguistic differences on the acquisition of Dutch compounds by French-speaking learners in the context of multilingual Belgium. Moreover, we explore the impact of additional target-language input through CLIL programs (Content and Language Integrated Learning) (Hiligsmann et al. 2017, Van Mensel & Hiligsmann 2023). The corpus data are drawn from the MulTINCo database (Meunier et al. 2023) and we will focus on the acquisition of Dutch nominal compounds (Hendrikx & Van Goethem, forthc.). The results are described and interpreted from the theoretical perspective of Diasystematic Construction Grammar (DCxG) (among others Höder et al. 2021), which conceptualizes the linguistic competence of multilingual speakers as one integrated network of constructions, containing language-specific idioconstructions and shared diaconstructions. References Balteiro, I. (2011). Awareness of L1 and L2 word-formation mechanisms for the development of a more autonomous L2 learner. Porta Linguarum 15. 25-34. Fradin, B. ...