Currently, the number of students participating in the film translation market in Vietnam is increasing. In English-Vietnamese subtitled films, the discourse marker appears with a fairly high frequency. The discourse marker is one of the key elements in language, especially in communication. With the connecting function, the discourse marker conveys many various meanings in the many contexts in which it is used. In this article, we mention an overview of the discourse marker and conduct specific research of the discourse marker “you know”. With these reasons, the article compares this discourse marker in English with the translated equivalents in the dialogues of the characters of the English-Vietnamese subtitled movie: “Mune- Chiến binh mặt trăng”. By analyzing the context that “you know” is used in the above film, we want to find out the similarities and differences in translating this discourse marker in the communication from English to Vietnamese.