Quantitative and qualitative methods were used to analyze the discourse expectations of formal classroom lessons in order to provide an informational base for curriculum-based language intervention. Samples of oral communication exchanges between general education teachers and their students in five classrooms each at first-, third-, and fifth-grade levels (15 total) were audiotaped. Grade level changes included significant increases in the syntactic complexity of teachers' language from third- to fifth-grade level, as well as findings that fifth-grade teachers conveyed content more frequently than first-grade teachers and that first-grade teachers called on students by name more often than either third- or fifth-grade teachers. Ten rules were generated from these discourse samples and from prior research to summarize the expectations that students must infer in order to participate successfully in formal lessons. Implications for students with communicative disorders are considered.