This paper focuses on developing a system of exercises on the rhetorical devices of word repetition and phrase repetition for Grade 5 students in accordance with the orientation of developing communicative competence—one of the core competencies emphasized in the 2018 General Education Curriculum of Vietnam. Based on an analysis of the psychological characteristics, cognitive development, and linguistic proficiency of primary students, the study identifies principles for designing the exercise system that ensure scientific validity, pedagogical appropriateness, practical relevance, and the promotion of learners’ activeness and creativity.