Abstract We test the claim that acquiring a mass-count language, like English, causes speakers to think differently about entities in the world, relative to speakers of classifier languages like Japanese. We use three tasks to assess this claim: object-substance rating, quantity judgment, and word extension. Using the first two tasks, we present evidence that learning mass-count syntax has little effect on the interpretation of familiar nouns between Japanese and English, and that speakers of these languages do not divide up referents differently along an individuation continuum, as claimed in some previous reports [Gentner, D., & Boroditsky, L. (2001). Individuation, relativity, and early word learning. In M. Bowerman, & S. Levinson (Eds.), Language acquisition and conceptual development (pp. 215–256). Cambridge University Press]. Instead, we argue that previous cross-linguistic differences [Imai, M., & Gentner, D. (1997). A cross-linguistic study of early word meaning: Universal ontology and linguistic influence. Cognition, 62, 169–200] are attributable to “lexical statistics” [Gleitman, L., & Papafragou, A. (2005). Language and thought. In K. Holyoak, & R. Morrison (Eds.), Cambridge handbook of thinking and reasoning (pp. 633–661). Cambridge University Press]. Speakers of English are more likely to think that a novel ambiguous expression like “the blicket” refers to a kind of object (relative to speakers of Japanese) because speakers of English are likely to assume that “blicket” is a count noun rather than a mass noun, based on the relative frequency of each kind of word in English. This is confirmed by testing Mandarin–English bilinguals with a word extension task. We find that bilinguals tested in English with mass-count ambiguous syntax extend novel words like English monolinguals (and assume that a word like “blicket” refers to a kind of object). In contrast, bilinguals tested in Mandarin are significantly more likely to extend novel words by material. Thus, online lexical statistics, rather than non-linguistic thought, mediate cross-linguistic differences in word extension. We suggest that speakers of Mandarin, English, and Japanese draw on a universal set of lexical meanings, and that mass-count syntax allows speakers of English to select among these meanings.