Aspecto inerente e passado imperfectivo no português: atua？？o dos princípios da persistência e da marca？？o

the main argument in this paper is to present evidences of the action of the persistence principle (hopper, 1991) and the markedness principle (givón, 2001) on the grammaticalization of portuguese past imperfective. from the quantitative point of view, the verb inherent aspect control shows that the aspectual feature [dynamism] determines the association between the forms in the expression of the past imperfective due to the pprog and imp aspectual histories, where the former is marked [+ dynamic] and the latter [- dynamic] for it also codes temporal distance. these results show that persistence and markedness may be considered converging motivations for the variation process in the expression of past imperfective.