This paper explores the acquisition path and interpretation of substance and object nouns in Yudja, a Brazilian indigenous language. Based on quantity judgment tasks (Barner & Snedeker 2005), we show that children accept both cardinal and non-cardinal interpretations for all nouns (object and substance denoting nouns), while adults strongly favor a cardinal interpretation for all nouns, including substance nouns. We will use the results from these studies to support three theoretical claims from the literature. First, that the pattern observed for adults corroborates previous analyses of Yudja according to which maximal self-connected concrete portions of a kind can be considered as atoms and can be counted (Lima 2014). Second, that counting does not require natural atomicity (cf. Rothstein 2010). Third, that the definition of atoms for counting is the result of lexical, syntactic and pragmatic factors and does not depend solely on the lexical meaning of a noun (cf. Srinivasan & Barner 2016).