摘要:ABSTRACT :Tense is an essential part of English. It is used in all English sentences. It isimportant to learn especially by students of English. Present perfect tense is oneof the tenses that has the same important functions. It is not easy for students tolearn about present perfect tense, the problem often shows up when they have todiffer this tense with other tenses especially past simple and present perfectcontinuous. This study is meant to find out the ability of second semesterstudent in English Department in understanding present perfect tense. The mainproblem analyzed in this thesis is the ability of second semester students inunderstanding the present perfect uses, especially in forming the past participle,making the correct structure of present perfect sentences, and also understandingthe differences between present perfect tense with other tenses (past simple andpresent perfect continuous). To find out the answers all of those problem, t- testis used. T-test is used. Ttest is a calculation technique that uses the mean of thegroup that is compared. With this t-test the differences between factors willshow.From the data which are processed through the t-test, it is found that theability of forming the past participle is bigger than making the correct structureand the ability of making the correct structure is similar to understanding thedifferences between present perfect and other tenses (past simple and presentperfect continuous).The main conclusion of this study is the ability of the secondsemester students of English Department is still poor