We investigate linguistic relativity effects by examining whether the grammatical count/mass distinction in English affects English speakers' semantic representations of noun referents, as compared with those of Japanese speakers, whose language does not grammatically distinguish nouns for countability. We used two tasks which are sensitive to semantic similarity, error induction in picture naming and similarity judgments, upon nouns referring to food items (English words and their translation equivalents in Japanese), and contrasted English speakers' performance to that of Japanese speakers. Results reveal that speakers of both languages are highly sensitive to semantic correlates of the English count/mass distinction, suggesting that the grammatical count/mass distinction in English does not affect English speakers' semantic representations in a language-specific manner, contrary to predictions of linguistic relativity theories, in which this grammatical property should exert language-specific effects on English speakers' semantic representations while they are engaged in language tasks. (Contains 14 footnotes and 2 figures.)