This paper reports on a study conducted to investi-gate the effects of using immersive virtual humans in natural multi-modal interaction to teach users cultural conversational verbal and non-verbal protocols in south Indian culture. The study was conducted using a between-subjects experimental design. We compared instruction and interactive feedback from immersive virtual humans against instruction based on a written study guide with illustrations of the cultural protocols. Partici-pants were then tested on how well they learned the cultural conversational protocols by exercising the cultural conventions in front of videos of real people. Subjective evaluations of participants' performance was conducted by three south Indian reviewers who were blind to the condition the participants were assigned. Objective evaluations of participants' performance were conducted on the motion tracking log data recorded during the testing session. We also measured the participants' pre and post positive and negative affect of training in both conditions, as well as the effect of co-presence with the life-size virtual south Indians. The results of our subjective evaluation suggest that participants who trained with the virtual humans performed significantly better than the participants who studied from literature. The results also revealed that there were no significant differences in positive or negative affect between conditions. However, overall for all participants in both conditions, positive affect increased and negative affect decreased from before to after instruction.