The aim of this study was to use crosslinguistic data from French-English bilinguals to test two models of past tense acquisition: (a) single route (all past tense forms rely on morphophonological schemas) and (b) dual route (irregular forms are learned as words, regulars through rules). These models make similar predictions about English acquisition, the focus of most previous research. French irregular verbs are often low in token frequency but high in family resemblance. Past tense forms of regular and irregular verbs in English and French were elicited from children between 3 and 5 years of age. Both models could explain most results. Two findings with French were more compatible with a single-route model, suggesting that this is a stronger explanation for crosslinguistic data.