The book explores classroom interaction of Iranian EFL teachers and learners. The purpose is to gain insight into minute details of classroom interaction comes about as a result of intervention in teachers teaching concept. Taking the perspective of Socio-cultural theory, the researcher first aims at conceptual change and follow-up classroom practice of two female elementary EFL teachers. Then,through critical reflection on their ongoing classroom practice, he replaces their routine concepts of what classroom practice and questioning should be like. Finally, he compares the classroom practice of the two intervention teachers with the two non-intervention ones. This way, he compares classroom interaction of the teachers and learners of the two groups regarding teachers' conceptualization of what classroom practice should be like, teachers' type of classroom questioning and learners' private speech markers. This work can be regarded as a milestone regarding how to explore classroompractice of teachers and learners in different educational settings.