We test the claim that acquiring a mass-count language, like English,causes speakers to think differently about entities in the world, relativeto speakers of classifier languages like Japanese. We use three tasks toassess this claim: object-substance rating, quantity judgment, and wordextension. Using the first two tasks, we present evidence that learningmass-count syntax has little effect on the interpretation of familiar nounsbetween Japanese and English, and that speakers of these languages do notdivide up referents differently along an individuation continuum, asclaimed in some previous reports (Gentner & Boroditsky, 2001). Instead, weargue that previous cross-linguistic differences (Imai & Gentner, 1997) areattributable to “lexical statistics” (Gleitman & Papafragou, 2005).Speakers of English are more likely to think that a novel ambiguousexpression like “the blicket” refers to a kind of object (relative tospeakers of Japanese) because speakers of English are likely to assume that“blicket” is a count noun rather than a mass noun, based on the relativefrequency of each kind of word in English. This is confirmed by testingMandarin-English bilinguals with a word extension task. We find thatbilinguals tested in English with mass-count ambiguous syntax extend novelwords like English monolinguals (and assume that a word like “blicket”refers to a kind of object). In contrast, bilinguals tested in Mandarin aresignificantly more likely to extend novel words by material. Thus, onlinelexical statistics, rather than non-linguistic thought, mediate cross-linguistic differences in word extension. We suggest that speakers ofMandarin, English, and Japanese draw on a universal set of lexicalmeanings, and that mass-count syntax allows speakers of English to selectamong these meanings.