In this paper I discuss the grammatical properties of container phrases in Yudja (Tupi; Brazil). I show that container phrases are syntactically indistinguishable from locative phrases. Based on two experimental studies with Yudja children and adults, I address two questions about the interpretation of container phrases. First, given that container constructions are identical to locative constructions in Yudja, could they be interpreted as simple locatives in constructions with numerals (i.e., indicating the location of a substance)? Second, when container nouns are overt in the sentences, do they necessarily refer to the unit being used for counting? Based on the results of these studies, I develop a compositional analysis of the locative interpretation of container phrases in Yudja.