This paper is a model-theoretic investigation into the count/mass dis- tinction in Slovene. It overviews and accounts for Slovene nouns, while also scrutinising Chierchia (2004)’s theoretical prediction that no language marks mass morphologically. I provide analyses of countability in the nominal domain of Slovene on semantic and morphosyntactic levels. Section 1 introduces the background notions and assumptions and thus provides the syntactic- and semantic-theoretic foundation upon which this paper rests. Section 2 overviews some cross-linguistic data from Greek, Lingala, Zuni and English that are problematic for the semantic theory of countability. Greek shows mass plurals (i.e. mass nouns that may pluralise) and Lingala, Zuni and English show mass/plural syn- cretism (i.e. nouns that are both plural and mass). This provides me with a cross-linguistic context within which the empirical evidence from Slovene may be mapped. Section 3 seeks to present the Slovene data: in the first part, count/mass distinction is presented paradigmatically, i.e. on the basis of Chierchia’s (1998a) ten-property system. The second part addresses some count/mass phenomena that fall outside of the aforemen- tioned system and specific to Slovene: mass extension and plural/mass margin. Section 4 deals with theoretical accounts of the data presented in the previous section. This section also comes in two parts: the first gives a semantic (lexical-compositional) account, and second translates the latter into morphosyntactic structures (using the tools and assump- tions from Distributed Morphology). Section 5 concludes the research by proposing that the count/mass distinction and various mass phenomena in Slovene may be accounted for phasally (Chomsky, 2001, et seq., Marantz, 2008).