The study seeks to investigate if and how Korean L2 learners' language modes vary across communication situations with two different types of interlocutors. The results show that in interviews with both Korean bilinguals and native English speakers, the subjects were found to be in the intermediate mode but in varied extents. The extent of the subjects' intermediate mode was found to vary according to the interlocutor. The total L1-driven or L1 language production in English was found to be significantly less in interviews with native English speakers than in the interviews with Korean speakers. In addition, different types of L1-driven data were found in the interviews by different types of interviewers. Among the types of L1/L1-driven data, the area "L1 semantics at a sentence level" was most prevalent in interviews with Korean bilinguals, while the more English-like forms of language (Konglish words) were mainly chosen in the conversations with native English speaking interlocutors. The factors that may contribute to the manifestation of language modes lie in differences between the two types of interlocutors such as physical appearance in terms of ethnicity and language use itself such as accent. (Daegu Haany University, Sookmyung Women's University)