This case study investigates the beliefs and practices of an English teacher in a senior high school in Magelang, Indonesia, regarding teaching speaking skills to adolescent learners. The study employed a single case study design. The result shows that the collaborator held a functional view of language, emphasizing communication as the goal of language learning. To achieve this goal, the teacher conditioned her students to use the target language and provided positive feedback to boost their confidence in speaking. However, the study also identified challenges students faced in mastering speaking skills, including a lack of confidence. The collaborator applies task-based language learning which promotes speaking skills and provides opportunities for students to use English in authentic communicative situations. This study provides insights into the beliefs and practices of an English teacher in teaching speaking skills to adolescent learners and the strategies used to promote these skills in the classroom.