Epistemic stance markers, such as je pense in French, take on a variety of discursive functions, ranging from asserting an opinion, indicating the source of information, and mitigating a claim, to pragmatic functions, such as gaining time for discourse planning. Previous research suggests that the epistemic marker je pense is mostly used in French conversation to express opinions and can be used as an indicator of the development of a learner’s assertiveness and pragmatic competence during a study abroad period. Using a functional approach, this paper seeks to find out the extent to which study abroad fosters the development of assertiveness and pragmalinguistic competence among L2 learners, through an analysis of stance marking in interview data from 26 Anglophone learners of French, who spent nine months abroad in a French-speaking country, and 10 French native speakers. The results show that learners are globally less assertive in their use of je pense than native speakers, particularly prior to departure, and that they develop pragmatic uses of je pense, thereby showing a development in their interactional strategies. Finally, the high inter-variability in the way learners used je pense suggests the importance of personal style.