The present study investigates attitudes, opinions, or characteristics of a group of heritage language learners of Korean in terms of teacher's language use in the US university foreign language classroom compared to those of non-heritage language learners. Data were collected through direct, first-hand observations, students' self-reports and questionnaires. Looking at the process of learning a foreign language, this study considers how foreign language teachers can address the complex histories of language learners by drawing on a qualitative as well as quantitative analysis of a foreign language class. The results of this study reveal that there were indeed no inter-language group (between heritage and non-heritage learners) differences in the perceptions of teacher's language use in the classroom. Both heritage and non-heritage learner groups have quite strong reactions to the teacher's use of L2 for the purposes of giving instructions, evaluating/commenting their oral performances, and building relationships. During the learners' reaction component of the study, most learners indicated that students' ability in the L2 most consistently affected the amount of L2 that teachers could use.