ABSTRACT
The research focuses on the codes used by the lecturers in English Department of Sebelas Maret University. The research was conducted to find the types of code switching used by the lecturers, why the lecturers switch code, and the functions of each type of code switching in teaching learning process. The researcher employs a qualitative descriptive study with field research. The researcher observes directly into the research location. The samples use purposive sampling technique. The data of this research are the teaching learning process done by the lecturers in English Department of Sebelas Maret University that employs the case of code switching. However, the researcher only takes some data as sample in representative each code switching that is found in the sources of the data. The source of the data are taken from the transcript of the recording taken by the researcher in skill classroom for first semester until third semester students of English Department to answer the problems statement. There are two types of code switching : metaphorical code switching and situational code switching. The data use both situational and metaphorical code switching employed by the lecturers during teaching learning process. The use of situational code switching occurs when there is a change of situation and participants. Meanwhile, the use of metaphorical code switching is converese and it relates with the component of the role relationships and communicative effects. Those components are important to convey the lecturers’ messages in delivering the material for the students. The types of code switching based on grammatical classification are divided into three : inter-sentential code switching, intra-sentential code switching, and tag switching. There are 10 functions found in the data which are based on the analysis done by using Gumper’z and Hoffman theory about the functions and reasons of code switching. The functions of code switching done by the lecturers in the data are : addressee, example, interjection, inquiry, emphasize, jokes, insufficient vocabulary resourches, personalization vs objectivization, explanation, and reiteration. Moreover, the findings show that inquiry, explanation, emphasize, and insufficient vocabulary resources are the functions of code switching which are mostly used by the lecturers during the teaching learning process. Keywords : code switching, lecturers, English Teaching learning process