This work investigates X-do type deverbal constructions, in order to determine whether such constructions are restricted to the class of adjectives or, on the contrary, they would also present properties that are also typical of nouns. Firstly, we consider the problem regarding word classes according to different perspectives, such as Traditional Grammar and Structuralism. Then, we discuss categorial conversion and its treatment in Traditional Grammar and Lexicalist Morphology. Also, we discuss the relation between the X-do type adjective and the past participle grammatical function. We approach the role of metonymy as well, in connection with X-do formations corresponding to patient or affected roles. Finally, we analyze specific cases, collected from O Globo newspaper for the period of two months. The appendix consists of tests elaborated in order to identify which formations occur as nouns formed by conversion and which occur only as adjectives. Conclusions are presented according to the results obtained through the application of the tests.