On the basis of data from English, French, Hebrew and Spanish, this paper argues that (apparent) adjectives which function as nominals belong to two distinct classes. One small class consists of true nouns that are homophonous with adjectives but are not derived from them. The other one consists of true attributive adjectives which modify a null N, and whose range of interpretations cross-linguistically depends on the conditions on the licensing and identification of null Ns in a given structure and in a given language. We further claim that while the former group can appear in any context where nouns are typically licensed, the latter group is restricted to strong environments. This, we argue, is because referential pro, the assumed head of N-ellipsis structures, is always definite.