I will illustrate and discuss the extent to which grammars may vary vis-à-vis the mass/count distinction with three main phenomena and use this as a springboard for outlining a theory of semantic variation, with a universal logical basis. The first form of variation concerns the most widespread empirical test associated with the mass/count distinction, namely how noun phrases (NPs) combine with numerals. The second is that of the so called ‘fake’ mass nouns (like furniture). The third concerns alternations between mass vs. count interpretations of nouns like beer or chicken.