This master thesis discusses the importance of noticing and understanding contextualization cues in a foreign language classroom, more specifically the use and understanding of contextualization cues in a secondary school EFL classroom and their importance in inferring the meaning of the context in classroom discourse, as well as the effects that certain contextualization cues can have on the classroom discourse and its participants. The paper first explains the importance of studying contextualization cues. This is followed by the explanation of the study that deals with how language in use is affected and shaped by the context in which it is used, namely the study of classroom discourse analysis. The following parts of the paper deal with the notion of context and the notion of conversational inference respectively, both of which are crucial for understanding the importance of contextualization cues since they are dependent on each other. The theoretical part of the paper is followed by the author’s research on contextualization cues in a secondary school EFL classroom which was done by observing classroom discourse in a classroom in a high school in Zagreb. The data for the research was collected by means of written notes from the observed classes, was analyzed and elaborated on with regard to the theory on the selected topic of the paper. In the end, the author’s interpretation of the importance of contextualization cues and their function in classroom discourse were given based on the examples from the observed classes.