EXPRESI BAHASA FORMAL DAN NONFORMAL YANG DIGUNAKAN OLEH SISWA DALAM KELAS INTERAKSI

An appropriateness to use language in particular situation is needed. Specifically in classroom interaction, when the students should use formal language instead of informal language. In fact, sometimes students use informal language in a formal situation. Hence, the researcher interested to analyze the factors influencing the use of formal and informal language expression used by English students in classroom interaction. The research is qualitative research. The participant of the research is the student of Postgraduate program of UNM. The data was taken in classroom interaction use interview guide as the instrument of the research. The result of this research shows that the students use both formal and informal language in classroom interaction. There are some reasons why they use formal and informal language in the classroom interaction. The data shows that there are six factors that influence students to use formal language. Those are; (1) adjusting language to the situation, (2) avoiding short utterance, (3) respect to the lecturer, (4) politeness, (5) academic reasons and (6) scientific reasons. There are seven factors influencing the use of informal language use by the student in classroom interaction. Those are (1) intimacy, (2) imitating previous speaker, (3) focusing on audience’s understanding, (4) habit, (5) simplicity, (6) spontaneity and (7) unconsciousness. Keywords : formal language, informal language, classroom interaction. Keywords : formal language expression, informal language expression, classroom interactio