The present work analyzes the subject of "code switching", which is found in multicultural societies, which we believe is also realized in the linguistic area at the universities outside the seminar room of the German departments. The aim of this study is to take the functions and structure of code switching also in and outside the seminar room through this analysis. This study is a case study. This study was conducted with six students made of three migrant students from the Faculty of Education Foreign Language Department – German Language Teaching Program. A 30 minute recording could be realized with this students. These students have chosen one of the three themes they were given and they were asked to make a discussion. These records were transcribed according to EXmAralda and examined from the viewpoint of the functional - pragmatic method according to its structure and function. The data showed that "code switching" also took its place in the guided free discourse. This linguistic action besides enhancing the common language knowledge of the students also enables the transfer of the language knowledge brought into the hall via the migrant children.Code switching is one of the complex and fruitful areas in sociolinguistics, thus, it has been studied in the linguistics at the universities outside the seminar room of the German departments. The aim of this study is to present the functions and the structure of code switching through analyzing actual code switching cases in and outside the seminar room. This study covers three types of code-switching classified as inter-sentential, intra-sentential and extra-sentential switches. This study is a case study and was conducted with six students three of whom are migrant students attending German Language Teaching Program of Faculty of Education Foreign Languages Department and the other three students are Turkish, who learnt German as a foreign language in Turkey. Recording of students’ conversations that took 30 minutes was realized with these students. These students have chosen one of the three themes they were given and they were asked to make a discussion. These records were transcribed according to EXmAralda and examined from the viewpoint of the functional-pragmatic method, developed by Ehlich / Rehbein and has a qualitative character. The outcome of this work is to work out code switching in a guided free discourse. The questions to be answered are as follows: 1) Does also occur in guided free discourse code switching? 2) What is the function of code switching in guided free discourse among German as a foreign language learners and migrant children? 3) Is there a difference in code switching between the guided free discourses and in actual the seminar room? 4) Does it contribute to the learning of the foreign language? (5) Is there a specific structure which may help to continue this form of work, or even to reject it? Findings of this study reveals that clarification and repetition, lack of language competence, the change of the discussion participants, explanations, solidarity function, and requests for help also occurs outside of the seminar room in the guided free discourse as properties of code switching. In contrast to Munukka's findings, the change of task between the participants, greetings and short phrases, individual support, discussion during partner exercises, grammar lessons, and disciplinary measures were not observed. The issues within the framework of codeswitching such as the change of tasks, the teaching and practice of the short phrases, the individual support of grammatical explanations and also disciplinary measures were not met. The simple answer might be the fact that such are the institutional tasks of the teachers, serving the purpose of the institution. In the discussion area outside the class, the authority of the institution is absence. This also gives the learner the opportunity to act freely. Here they are the authority itself, where the self-control and the support of the discussion depends on the participants. In this discussion areas the migrant children take over the role of the teacher. They support the -learners in the lack of vocabulary and try to stay as far as possible in the main discussion. They allow the German as a foreign language learners enough time to think, usually taking about 4 seconds in the transcription, where the discourse would normally have to be broken, so that the German as a foreign language learner can participate in the discussion at all. They support the German as a foreign language learner to take part in the discussion, although they try to hold the main talk. Each participant showed a great approval in this discussion round. The German as a foreign language learners asked for help, where they did not progress. They used code switching as soon as they realized that they could not contribute to the discussion. The code switching to the first language usually took place by the one tone of a lower level of conversation. Thus, it can be said that in discussions, two levels of discourse can be located in order to be able to live up to the goal of this meeting. In this study the structure of code switching is shown in intrasentential and inter-sentential code switching. In the case of deficiency of vocabulary, understanding insure, etc., they prefer the intra-sentential code switching, in which comments on the subject are inter-sentential character. There was no extra-sentential code switching in the transcriptions. The student SC was the only one who tried to carry on the conversation by particles which only occurred in the target language. Within the utterances no one of the participants encounter an extrasentential code switching in either the first or the second / foreign language. This linguistic action of the learners also shows that the learners are aware of the goal of this discussion. Even though this group work was realized outside the seminar room, the aim of this meeting is to practice of the foreign language and it’s also subject of the institution. The findings of the study suggests that migrant children have a great influence on the German as foreign language learners in and out the seminar room. The migrant children contribute to the processing of the competence of the German as a foreign language learners in Turkey. Learner-centered tasks, such as the discussion round, also help to ensure that migrant children and German as a foreign language learners work together more firmly. Since a censorship is also removed by the teacher gives them a freer room for action confirming their cooperation. At least this study showed that "code switching" also took its place in the guided free discourse.