Written syntactic complexity is considered in relation to the four modes of discourse (argumentation, exposition, narration, and description). In a study of 153 children at three ability ranges within each of three grade levels (three, four, and five), syntactic complexity was found to differ significantly across the modes. The range of syntactic variability within one grade was found to almost equal syntactic maturity potential up through the twelfth grade. Writing development is discussed as an internally predisposed process stimulated by varying syntactic challenges. Implications for the development of language competence and cognitive processes are considered. (Author/AA)