Sumerti Riwu Pengarang GRACIA M. N. OTTA Dosen Pembimbing 2 Johnson W. Haan Dosen Pembimbing 1 Novriani Rabeka Manafe Penguji 2 Gracia M. N. Otta Penguji 1 Johnson W. Haan Ketua Penguji

The aims of this research are to know how grammatical the use of adjective clauses by class D of the fourth semester students of English study program of Nusa Cendana University, the aspects of relative clauses in English that have been mastered by the students and the aspects of relative clauses in English that have not been mastered by the students. This research used descriptive qualitative method. The subject of this research was class D of the fourth semester students of English Study Program of Nusa Cendana University. To collect the data, the writer used written text.From the data collection, the writer found that there are 7 of 8 adjective clauses used by the fourth semester students of English Study program of Nusa Cendana University in their written text. The relative clauses are: who, whom, which, that, where, when, and why. To know aspects of relative clauses in English that has not been mastered by the students.Based on the data analysis, the writer concluded that the aspects of adjective clauses that have been mastered by the fourth semester students of English Study Program of Nusa Cendana University were: where, when, and why. While, the aspect of relative clauses that have not been mastered by the students were: who, whom, which, and that