This book argues that, in line with the tenets of positive psychology in SLA and the rhetorical/relational goal theory, positive teacher-student interpersonal relationships are deemed to be of great significance for empowering students to accomplish favorable academic outcomes and to successfully learn a second/foreign language (L2), whether at its affective, behavioral, or cognitive levels. Therefore, understanding the role of teacher interpersonal behaviors and their effect on students' learning gains in the domain of SLA is of utmost importance, particularly as this line of research is at...