The paper develops Pires de Oliveira’s (2020, in press) model theoretical approach to Brazilian Portuguese (BrP) and English. BrP and English are number marking languages, ie when n is first projected, little-n, [n 0 [X]], where X is a non-categorized root, it is projected as a predicate, <e, t> (Chierchia 2010, 2014, in press). The proposal distinguishes the denotation of n 0 from the denotation of a plurality of atoms. The nominal n 0 denotes a part-whole non-atomic lattice (Rothstein 2010, 2017). In English, atomicity is mandatory immediately after n 0 : n 1 is projected, generating [n 1 [AtP [n 0 [X]]]. This predicts no Bare Singulars in argument position in English, mass interpretation via coercion, and also that nominal root [n 0 [X]] surfaces in English when AtP is not projected, as in compounds. In BrP, [n 0 [X]] surfaces in argument position, because AtP is not mandatory after little-n. This is the bifurcation separating these two types of languages. The absence of grammatical atomicity, leads to under-specification of mass and count. Thus, the Bare Singular is neither mass nor count. Atomicity is induced by the “determiner”, understood in a broad sense: plural inflection, the definite article, some quantifiers. It explores an unitarist approach to the nominal phrase in BrP and proposes a non-canonical derivation. The conclusion explores variation in number marking languages.