I have finished the MA course in English linguistics, and it is time for me to complete the final thesis which partly shows what I have got from this very useful programme. There are many things to write about but I choose to study on Relative clauses in English and its representatives in Vietnamese using Systemic Functional Grammar as the theoretical framework. This is because of some reasons. On the one hand, in linguistics history, English grammar has been described in different ways such as in Chomsky’s Transformational Generative grammar, in Bloomfield’s Immediate Constituent grammar, and in Halliday’ s Functional grammar; however, it can be thought that the latest is the most successful in ‘bringing language closer to life’. As Thompson (1996:6) states “it is a full analysis of sentence in both form and meaning as well as their relationship”. Therefore, it is reasonable to use functional grammar system in my study. On the other hand, I found many Vietnamese learners are experiencing a lot of difficulties when learning to use English relative clauses. They make many mistakes in making clauses containing relative clauses such as lack of relative pronouns, lack of subject-verb agreement. They sometimes say or write some funny Vietnamese sentences which are not pure Vietnamese simply because they translate improperly clauses containing the relative clause in English into their mother tongue. Being a teacher of English, I like to know whether my knowledge of English relative clauses can be used to help my students deal with the problems. Furthermore, I also like to introduce functional grammar to my students as it is a very useful way to look at English grammar as a live system in English language and to study and apply English grammar more appropriately. Because of the above mentioned reasons, my final thesis is entitled “Relative clauses in English and in Vietnamese: A systemic functional comparison”. I hope this study will help my students and all concerned understand and use English relative clauses more easily. I also hope that this study will be useful for them when translating relative clauses in English into Vietnamese and vice versa.