This study aimed to develop supplementary speaking instructional materials to enhance the English linguistic competence of Grade 9 students. An analysis of 178 students' speaking skills found their pronunciation was slightly unclear, intonation and stress were moderate, voice projection was erratic, and diction and fluency were limited. The developed materials incorporated daily life and work contexts using Nunan's instructional model. Teachers found the materials very useful for improving students' speaking skills and recommended including authentic experiences and activities. The study concluded task-based speaking materials are effective for developing oral communication abilities.