Adjacency pair is an essential part in which sequences in conversation are formulated. It is formed by two utterances produced by different speakers related to one another. In the teaching-learning of EFL, it can be found in interpersonal dialogues in the English textbooks. It is necessary to investigate the adjacency pairs in textbooks because it is helpful for the teacher's guidance in giving the speaking lesson. Thus, this research aims at analyzing the adjacency pairs in interpersonal dialogues found in the textbook "When English Rings a Bell" for seventh grade students of junior high school (revision 2017). This research applied descriptive qualitative research to describe a phenomenon of adjacency pairs found in the textbook. The researcher used field notes as a researcher tool in collecting the data, and the researcher analyzed the data using a theory proposed by Paltridge (2006) regarding adjacency pair types. The results revealed six out of eleven adjacency pair types used in the textbook. They are greeting-greeting, question-answer, assessment-agreement, leave-taking adjacency pair, compliment-acceptance, and offer-acceptance. In addition, the insertion-expansion process occurred because the second speaker wanted to expand the conversation. It is done by clarifying the utterance produced by the first speaker. It is concluded that adjacency pair types and insertion-expansion process is involved in the textbook. Based on these results, it is suggested for English teachers to include these in teaching and learning activities through the dialogues in the textbook in order students can create more interactive conversation in actual practice.