According to Castro (1991) and Cardeira (2005), the 15th and the early 16th centuries are considered a transition period from the medieval language to the classic language in which forms from the old language coexist with forms that foresee the Portuguese of the classical language. Based on Castro (1991) and Cardeira (2005), and also on the notion of "grammars in competition" (KROCH, 1994), we argue that a transition period should be characterized by the instability resulted from the combination of the new grammar signs that intersected with the old grammar forms. In this paper, we shall present some evidences from the clitic syntax in old texts written by authors born between the 15th and 16th centuries; evidences that may confirm the hypothesis of grammatical instability and grammars in competition during this period.
Syntax; Interpolation; Syntactic change; Diachrony; Generative Grammar
