Languages differ in their preferences for particular intensifying constructions. While intensifying adjectival compounds (IACs) (e.g. "ijskoud, ice-cold") are productively used to express intensification in Dutch and English, in French this construction is hardly productive. Consequently, French-speaking learners may encounter difficulties acquiring IACs in Dutch/English. As part of a research project on CLIL in French-speaking Belgium, we explore the effect of CLIL on the acquisition of IACs in the target language (TL) Dutch/English through a multiple-choice test. The results confirm that CLIL students (learning English/Dutch) develop greater receptive knowledge of these constructions. Furthermore, the more frequent IACs are more likely to be recognized by the learners. Moreover, even when the CLIL effect is considered alongside other factors, such as the students' extracurricular exposure to the TL and their overall vocabulary, CLIL is still an important predictor of the learners' receptive knowledge of English IACs, in addition to productive and receptive vocabulary. By contrast, current informal contact with the TL and receptive vocabulary are significant predictors of learners' receptive knowledge of Dutch IACs, but CLIL does not significantly contribute to the regression model for the latter language.