Dissertation (MA Education)This study focuses on designing and evaluating grammatical trial material for enhancing communicative competence in Tanzanian secondary schools. The aim was to design learner centered instructional grammatical material that supports English teachers on implementing the Competence Based Curriculum in order to enhance English Language communicative competence for Form One students. Constructivism theory and language acquisition to material development theory guided the design based on activities throughout the stages of Learner centered instructional grammatical material. The study adapted quasi-experimental and phenomenological designs using treatment and control schools. Data were collected through documentary review, interviews, questionnaires, observation, and pre/post tests. The findings and observations from the study revealed that, there was a relationship between students learning with designed activity-based grammatical materials and improved performance in students. Both teachers and students were found to be more interested in learning with the materials. The materials seemed to be effective in enhancing communicative competence for students towards the implementation of competence-based English Language syllabus. The study concludes that although teachers are aware of Competence Based Curriculum, they do not practice it in classroom. The Designed approach showed to raise teachers‟ content and pedagogical knowledge on teaching grammar using Learner Centered Approach. The study recommends other studies to be undertaken on designing similar instructional grammatical materials for other levels in secondary education in order to enhance communicative competence for students.