The proficiency of elementary school students in grammar is essential for developing their language skills, both in written and spoken communication. However, teaching students' grammatical competence at this early stage presents challenges, as traditional methods often fail to capture the nuances of their developing understanding. This article discusses the importance of designing effective criteria for evaluating grammar proficiency in elementary school students, providing a framework for understanding the key components of grammar that should be taught. It emphasizes the role of formative teaching and practical evaluation tools in monitoring students' progress while focusing on how these criteria can guide instructional strategies. The article concludes with recommendations for designing more comprehensive and age-appropriate teaching criteria, ensuring a holistic approach to evaluating grammar proficiency in young learners.