This study examines the developmental path that native speakers of Canadian French follow when acquiring the prosodic representations underlying English primary word stress. It has been proposed that Canadian French has a single iambic (i.e., unstressed-stressed) foot right-aligned in the Prosodic Word (e.g., Charette, 1991; Goad & Buckley, 2006). By contrast, English has been analyzed as having a trochaic (i.e., stressed-unstressed) foot sensitive to syllable weight (e.g., Hammond, 1999; Hayes, 1995). A nonsense word production task was administered to determine if French Canadian second language (L2) learners of English can reset foot headedness to the left and align the head of the foot with heavy syllables. A clear developmental path emerged from the results, with most L2 learners abandoning their native language grammar and acquiring the trochaic foot as they became more proficient in English. Furthermore, only the L2 learners who had acquired the trochaic foot could align its head with heavy syllables, suggesting that the development of L2 prosodic representations unfolds in a precise fashion. However, many L2 learners failed to align the head of the trochaic foot with heavy syllables, a problem which persisted even among the most advanced L2 learners. These findings are discussed with respect to the properties of the input and to the prosodic structure of Canadian French.