In this paper we discuss the traditional and the functional approach to Portuguese language teaching. We focus on contributions of functional researches on different linguistic phenomena taught in elementary and high school, such as transitivity, relative clauses and forms of degree. Founded on Usage-based Functional Linguistics (Martelotta, 2011; Furtado da Cunha, Bispo, Silva, 2013), we show an alternative approach to those phenomena which are in accordance with Parâmetros Curriculares Nacionais (PCN).