Discourse is language in use (Brown & Yule, 1983). It is frequently understood as the largest and most complete unit of language structure, it means that discourse is part of a series of language components. This perspective discourse has been analyzed for its role in expressing ideologies, power, dominance, inequality, and bias (Van Dijk, 1998). In Linguistics, discourse has also been viewed from different perspectives, referring to other types of languages used in various sorts of social situation such as newspaper discourse, advertising discourse, classroom discourse, and the discourse of medical consultation (Fairclough, 1992:3). Thus, it can be defined that Classroom Discourse is language use in a classroom context as a mean of interaction between teacher or lecturer and students during a classroom interaction. This study aims to investigate the forms and functions of verbal communication used by teacher-lecturer and students in classroom situation which serve a particular pedagogic purposes and concerning lecturer’s politeness, speech acts and cooperative principles in the classroom. The research method applied in this study is a descriptive qualitative approach based on the transcription among models of classroom discourse- the Sinclair and Coultrhard (1975) model. The Didactic Triplet that refers to a specific sequence of three conversational turns; Initiation, Response and Follow- Up. As the result of this study, observing classes, finding out some datas from class Y6H on the 6th semester about teacher’s monologue, Instruction and Participation and also Conversation Analysis Contribution To Classroom Discourse. Finally, it is understood that there is asymmetrical role between teacher- lecturer and students in the classroom discourse. Teacher- Lecturer controls patterns of communication by managing both the topic of conversation and turn taking while students take their cues from the direct most of the responses in classroom interaction.