This study is entitled the error analysis on the use of irregular verbs by second year students of SMPN 7 Banda Aceh. This study focuses on the analysis of both spelling and forms of irregular verbs, particularly past form, past participle, and present participle. The goal of this study is to find students ability on English irregular verbs made by students of SMPN 7 Banda Aceh by conducting an analysis on error. The method used in this study is descriptive qualitative analysis. The samples chosen were students from class 2-1, 2-3, and 2-5 second year students using a quota sampling model. The instrument was a test, that is a discrete-item test (completion item) consisting 48 questions. The test was conducted on 22 February and 13 March 2010 taking place at SMP 7 Banda Aceh, In data analysis, the study applies an item analysis. The result shows that students' errors in form and spelling are 61.1% in
total; correct answers are 35.3%; and the rest answers are empty or 3.6%. Meanwhile errors for forms are divided into past form 23.34%, past participle 24.91 % and present participle 9.08%. On the other hand, the finding shows that students are mostly weak on past form and past participle of irregular verbs.