In Taiwan, English education has been incorporated into primary school curriculum for years, and yet the effects of teaching grammar to children still remain unknown to English teachers and researchers. The existing research findings underlined the necessity of exploring the acquisition of English grammar rules by elementary school students. The inductive and deductive approaches for grammar teaching were therefore investigated in this research. The findings suggested that students taught using either approach were capable of comprehending and acquiring the target grammar. However, students in the deductive group significantly outperformed those in the inductive group. Furthermore, participants in each group expressed both positive and negative attitudes toward the instructions.