摘要：Nowadays, learning English is very important because English is one ofinternational language which is usually used for communication by wholecommunity. There are some parts of learning English. One of the essential partsis grammar. Grammar is very necessary when we want to do a written English.For example we can learn sentences, tenses, parts of speech, prepositions,clauses, and so on. The Problems identified in this research were: how was theability of understanding adjective clause of the third year students faculty ofletter Gunadarma University? and what problems faced by the third yearstudents in mastering adjective clauses ? The objectives of the study were: tofind out the ability of understanding adjective clauses of the second yearstudents, and to analyze the problems faced by the third year students inmastering adjective clause. The writer used the library research and the fieldresearch to complete the accomplishment of the scientific research paper. In thelibrary research, the writer used some books which were related to the topic tohelp the writer in finding theories about adjective clause. The writer alsobrowsed theories from Internet to add theories beside from the books. In thefield research, the writer used qualitative and quantitative methods by givingquestionnaires randomly to 110 populations in 3 SA 01, 3 SA 02, and 3 SA03Faculty of Letters Gunadarma University. Then the writer only took 38populations as the samples in this research. The samples were then analyzed pernumber in each questionnaire and were concluded to the ability based on theaverage score, total correct answers, and the percentages. The writer found thatthe ability of the third year students of Faculty of Letters in understandingAdjective Clauses was below average or poor. The problems faced by thestudents were: most of them still did not know the use and the functions of eachrelative pronoun in adjective clauses which are who, whom, whose, which, ofwhich, and that.
