When writing a text, the choice between seemingly equivalent connectives, such as but and however, is not arbitrary: aside from preferences linked to the register or modality of the utterance, there are often pragmatic or syntactic constraints that limit the choice to only one particular connective. For French, theoretical approaches have extensively dis-cussed the syntactic and pragmatic constraints that allow only either parce que ('because') or puisque ('since'). However, experimental findings regarding the actual sensitivity of French speakers to these constraints remain inconclusive. In the current study, we examine the sensitivity of different speaker groups to the constraints associated with the use of parce que and puisque. In a controlled offline-task, we systematically evaluate the sensi-tivity of a crowd-sourced heterogeneous group of native speakers (Experiment 1) and a group of non-native speakers (Experiment 2). Results show that native speakers are more sensitive to syntactic constraints whereas pragmatic constraints are more equivocal. Non-native speakers, however, are not sensitive to either of these constraints. In addition, the pragmatically complex connective puisque is extremely problematic for non-native speakers, as even the mapping of a seemingly equivalent connective of their L1 did not warrant a good mastery of its pragmatic functions.(c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).