Purpose: This study aims to explore the communicative features of teacher talk in English for General Purposes (EGP) vs. English for Academic Purposes (EAP) classes in Iranian contexts based on the Self-Evaluation Teacher Talk (SETT) framework. Design/methodology/approach: For the purposes of this study, EAP and EGP classes run by three language instructors and three content instructors were observed and interviews with teacher participants were conducted. The data were analyzed by content analysis, and emerging overarching themes were recorded. Findings: The findings of this study indicate that the translation of texts into Persian was the dominant theme in classes run by content instructors who were less aware of the communicative features of teacher talk. However, one of the content instructors who was familiar with the communicative features of teacher talk as well as general language instructors were found to be highly aware of the potential of their teacher talk to encourage communication in his classes. The innovative and communicative features in the language/content instructor suggest the importance of teacher agency in bringing change in education at the micro-level. This study has implications for various agencies involved in teaching EAP, EGAP and English for Specific Purposes (ESAP), raising awareness regarding the communicative features of teacher talk as a driving force leading learners and teachers to more communicative opportunities in language classrooms. The findings suggest that teacher talk is an essential component of classroom discourse, shaping students' linguistic and academic development, and that teacher agency is crucial in promoting communicative opportunities in language education. To boost communication, the authors recommend translanguaging with a focus on both communication and optimal use of the mother tongue in EAP classes. Originality/value: There is little empirical evidence on the communicative aspects of teacher talk in higher education. This study can inspire more parallel research on EAP settings in higher education with a focus on communication and teacher talk features.