In learning a language, making errors are the natural thing and sometimes difficult to be hindered by the students. The students sometimes omit the necessary items, add the unnecessary items, misform items even misorder them. Therefore, the students should pay attention to the grammar of the language to hinder the same errors. Therefore, the researcher conducted a research to know the types of grammatical errors, the commonest one and the causes of those errors. This research employed descriptive qualitative approach. The population of this study was the second semester students of English Education Department of Teacher Training and Education Faculty of University of Islam Malang in academic year 2020/2021. The researcher took 10 papers of students’ personal narrative as the sample of her research. The finding showed that the second semester students made errors in all types of surface strategy taxonomy such us omission, additions, misformation and misordering. The most common grammatical error made by the students was misformation with 56 or 58.3% errors and the causes of students’ grammatical error were interlingual and intralingual transfer. It can be concluded that the students' understanding toward English grammar was still low. They were also still influenced by their mother tongue and the students still had a lack of knowledge about the target language. Therefore, the lecturers should apply the other technique in their teaching to improve the students’ understanding and motivate them to read English writings in order to be familiar with English rules. Further, the students should be more aware to the rule of the target language. Last, this study also can be a reference for the future researchers to conduct more depth study. Keywords: Analyzing, Grammatical Errors, Narrative Text