The paradigm of possessive determiners differs in systematic ways across languages and causes cognitive resolution problems in the interpretation of a foreign language. Based on previous investigations into cross-linguistic influences (CLI) in learners’ interpretation of possessive determiners, this article presents the design of an experiment for testing English, German and Norwegian adult learners of French. We specify two kinds of processing problems: a direction problem (orientation towards possessor vs. possessee) and a problem of lexical parasites (‘false friends’). The experiment is directed at learners’ spontaneous interpretation of the singular possessives "son", "sa" and "ses", on account of a partly false friendship with the possessive determiners in these learners’ first languages.