The purpose of this article is to present how in the learning and teaching of Portuguese as a mother tongue the concept of formative evaluation becomes meaningless when used as a magic wand to transform practices while neglecting the analysis of epistemological foundations and didactic consequences of the corresponding representations. In order to prove the legitimacy of a real regulative evaluation in the development of discursive competences, this article also examines misinterpretations motivated by the fetishizing of the concept such as the presumed interdependency of evaluative practices, the qualitative aspect of evaluative objects and also the continuous and processual aspect of evaluative practices.