The main purpose of the study is to refer to the opinions of students on the use of mother tongue in German grammar lessons, and to reach a perspective on whether the use of mother tongue in German grammar lessons is necessary or not. In this study, the phenomenological pattern, which is one of the qualitative research methods, was preferred and a semi-structured interview was conducted with 15 volunteer students from the first and second classes of the German Language Education Department of Gazi Faculty of Education. A total of seven questions were asked to the relevant students. The NVivo 12 program was used for data analysis. The data obtained was transferred to the relevant program and categories and subcategories were created. According to the student opinions obtained from the data, it was found that the use of mother tongue in German grammar lessons has an important effect. It is seen that the use of mother tongue in German grammar lessons is supported by the students in question. Some students express that they cannot practice in the related language by thinking that the use of mother tongue in foreign language classes prevents being exposed to the target language. Although there are some negative aspects of mother tongue use in foreign language classes, it is determined that referring to the mother tongue in grammar lessons increases the understandability of grammar topics according to student opinions. It is also observed that by referring to the mother tongue in German grammar lessons, students have the opportunity to make comparisons between their mother tongue and the target language, they can see the similarities and differences between the two languages, and they can better understand grammar topics in their mother tongue.