The purpose of this study was to investigate the relationships between teachers’ specific discourse and behaviors with students’ motivation. Data were collected from fifty two Korean high school girls using semi-structured interviews. Because self-efficacy and achievement goals are known to play particularly important roles in students’ adaptive learning processes in school, we aimed to identify specific comments and behaviors of teachers that affect students’ academic self-efficacy and achievement goal adoption. We were also interested in validating the motivational mechanisms suggested by each of the theories with students’ responses. By asking students about the comments and behaviors of teachers they generally like or dislike, we were able to examine the degree of commonality between these responses and those related to particular motivational constructs. Students’ responses were largely consistent with previous findings as well as the mechanisms delineated by each theory. Students reported that they disliked teachers’ comments that put excessive emphasis on grades, preferential treatment of students by test scores, public comparison of students’ performances, and punishment without a clear explanation on the reasons why. Not only these are the comments and behaviors of teachers most disliked by the students, they were also mentioned as the comments and behaviors that lowered students’ self-efficacy and led them to adopt performance goals in achievement contexts. Whereas students’ responses on the comments and behaviors they disliked, lowered their self-efficacy, and led them to performance goals showed remarkable consistency, those regarding more positive aspects of teachers’ discourse and behaviors varied substantially across questions. Students listed different omments and behaviors as the ones they generally preferred, that increased their self-efficacy, or that encouraged them to pursue mastery goals in learning situations.