Following the framework of contrastive linguistics (especially Gast 2012), intensification of adjectives is taken as a tertium comparationis that allows a function-based approach of how different languages hypothetically use different linguistic forms to express the same ontological category. Using contrastive analysis to “describe[s] one language from the perspective of another†(König 2012: 22), we will study how intensification of adjectives is used and formally realised in the trilingual output of native French speakers in spoken French, non-native English and non-native Dutch. Learner language is considered as language showing features of the L1 of the learner (Gast 2012: 7), which allows for an assessment of the extent to which L2 users are able to use foreign languages with the same diversity of constructions and of semantic nuances as in their L1, while using constructions that are more typical of the L2. Intensification has been extensively described in terms of its semantic (Paradis 2001) and formal properties in English (Bolinger 1972, Ito & Tagliamonte 2003), Dutch (Broekhuis 2017, van der Wouden & Foolen 2017), and French (e.g., Riegel et al. 1994). These studies show that languages use a wide variety of constructions to express intensification, but that language-specific preferences can be observed (cf. Rainer 2015). Also, intensification has been studied from a second language acquisition perspective for non-native English (Granger 1998, Lorenz 1999, De Haan & van der Haagen 2012) and for non-native Dutch (Hendrikx et al. 2017), with a focus on learner writing. However, to our knowledge, no study of the kind has been conducted on speech corpora and no study took a cross-linguistic view on the semantic types of intensification into account. Beyond this, the contribution aims at exploring the effect of Content and Language Integrated Learning (CLIL) on the use of intensification in the foreign languages under study. More specifically, we address the following research questions: i. ...