This study aims to evaluate the impact of task-based learning and graphic organizer techniques on enhancing student teacher professional competency in English listening and speaking skills. The study used a One-Group Pre-Test Post-Test Design, which involved 30 undergraduate math-major students in a Thai public university. Over eight weeks, the study group was instructed using teacher-prepared materials delivered through task-based learning and graphic organizer techniques. Pre- and post-tests were conducted to measure listening and speaking proficiency progression. In addition, the participants completed a self-evaluation form with professional competencies relating to listening and speaking before and after the study to measure the extent to which they have progressed. The results showed a significant improvement (p < 0.05) in listening and speaking proficiency, with learners advancing from beginner to independent user levels on the CEFR Global Scale. While most learners demonstrated substantial improvement, some showed moderate progress. This research emphasizes the potential of task-based learning and graphic organizer techniques as an effective method for tertiary-level undergraduate EFL student teachers. The findings offer valuable insights for designing and implementing language learning programs, emphasizing the importance of learner commitment and motivation. This study can serve as a practical guide for similar learner populations and provide implications for future language learning initiatives.