This study investigates the effectiveness of Task-Based Language Teaching (TBLT) in
promoting students' speaking sub-skills. The background of this study stems from the
challenges faced by EFL students in an Islamic Senior High School in Duren Mekar,
Depok, West Java, Indonesia, including fear of making mistakes, limited vocabulary, lack
of speaking partners, and monotonous teaching methods. This research employed a
qualitative action research design involving eleventh-grade students as participants. Data
were collected through observation, interview, and documentation across three cycles of
implementation. The speaking sub-skills assessed in this study were based on Harris's
(1974) framework, which covers pronunciation, vocabulary, grammar, fluency, and
comprehension. The findings reveal that the implementation of TBLT brought significant
improvements across all five speaking sub-skills. Students demonstrated progressive
enhancement in pronunciation accuracy, lexical components, grammatical control, fluency,
and comprehension throughout the three cycles of action research. The results indicate that
TBLT, through its structured stages of pre-task, task cycle, and language focus, effectively
engages students in meaningful, real-life communication tasks that foster speaking
confidence and proficiency. This study concludes that TBLT is a valuable and effective
teaching approach for promoting students' speaking sub-skills in the EFL context,
particularly in boarding school settings.

Keywords: Task-Based Language Teaching, speaking sub-skills, EFL Classroom