Findings from 10 projects, sponsored by the National Institute of Education, which focused on teaching as a linguistic process, are examined in this paper, along with findings from related studies. The projects constitute first-generation indepth studies of selected classrooms and are discussed in relation to two aspects of the linguistics of classroom environment. The first section explores findings in terms of the differentiated nature of classroom activities, behaviors, and requirements at group and individual levels. The second section combines information about features and outcomes of discourse and relates the data to student academic achievement. The subjects of the projects and their principal investigators are: (1) interpersonal relationships during playground games (Borman); (2) social and cultural organization of bilingual classroom interactions (Cazden and Erickson); (3) effect of classroom organization on learning of classroom discourse rules (Cole); (4) cooperative and didactic interaction patterns (Cooper); (5) learning of discourse rules by culturally different children (DeStefano and Pepinsky); (6) school/home ethnography (Gumperz and Simons); (7) ethnographic and ethnolinguistic patterns of discourse and learning in and out of school (Hymes); (8) children's groups in school (Farnham-Diggory); (9) the contribution of service-like events during individual work time (Merritt); and (10) participant perspectives of classroom discourse (Morine-Dershimer and Tennenberg). (FG)