Writing is a proficiency which is very difficult and complex. This is because the learner needs many aspects to master, such as lexical aspect, grammatical aspect, the ability to present facts and express their thoughts, etc. According to the results of the final review of the 4th semester students, we found that students have encountered a lot of grammatical errors in the course of writing. As a result, we search for analysis to identify this problem and find solutions. Therefore, the problem proposed in this research is: 1) what type of error is often done by students in the course of writing? (2) What is the grammatical error which is found a lot depending on the result type? (3) What are the solutions to solve them? In order to find answers to this problem,we did a descriptive qualitative research with qualitative method by analyzing of the errors. We found that: 1) the dominant type of error is the grammatical error, 2) the most significant type of grammatical error is the error of the adjective. So, in order to solve the problems, students must have a good grammatical skill in the first half; we have to make the students know their grammatical errors even if it’s very simple, give more exercises in the students so that they are used to write correctly
In this research, we gave a grammar test to students of the second semester, in total 50 questions, with the type of test « Closure test » in the matter of the passé composé and imparfait. Then, from the result of this test, we analyze the grammatical errors made by the students. So, this study entitled « Analysis of grammatical errors at past tenses by the students of the department of French UPI of second semester academic year 2017/2018 ». The purpose of this research is to describe grammatical errors made by the student. The research method used in this research is descriptive qualitative, and the dataswere obtained from the analysis of test results. Based on the analysis, we were able to conclude that the forms of errors are made by students is the conjugation error, the usage of auxiliary error, without the auxiliary, without agreement and error of the usage between the passé composé and imparfait in complex sentences and in a text. The main factor causing these errors is the neglect of students to answer questions and the lack of understanding of students to use the passé composé and imparfait in complex sentences and text.

