Dyadic teacher-student interactions represent a potentially valuable opportunity for adolescent emergent bilingual students to access academic knowledge, develop language proficiency, and acquire literacy skills in secondary school contexts. But to what extent are these conversations actually an affordance for students? Drawing upon insights in interactional sociolinguistics, conversation analysis, and other classroom discourse research, this study analyzes interactions during in-class writing activities between teachers and Spanish-speaking adolescents at beginning and intermediate levels of English proficiency. Data indicate that students often tend to offer agreement or limited responses in interactions related to language use, generating ideas, factual knowledge, and conceptual issues. Analysis of discourse includes a focus on both the dilemmas teachers face in interpreting students' limited contributions and teachers' interactional and interpretive roles in these interactions. (Contains 1 table.)