Grammar is one of the important aspects if it comes to academic purposes. Therefore, this study aims to investigate the grammatical errors in students’ writing and the student’s abilities to correct their errors. The study was conducted using a document analysis technique, and the participants were 32 first-semester students of the Basic Reading and Writing class. The 2 research questions: What are the most frequent types of grammatical errors that students make in English writing? And to what extent can the students correct their errors? The analysis results show the most frequent grammatical error types are Concord/Agreement (201), Tenses (65), and Verb Group (47). Moreover, the students mostly still have difficulties in analyzing and correcting their errors. Concord/ Agreement (69%) is found to be the highest error percentage. Based on the results, this study can be beneficial for 3 groups: ELESP, ELESP students, and Future Researchers.