This study investigated the effectiveness of a thematic approach in teaching grammar to elementary students in Grades 4, 5, and 6 at Villa Alcaria Elementary School. Here, using a quasi-experimental design, 95 learners were divided into experimental groups, which received grammar instruction integrated with thematic content areas, and control groups, which followed traditional grammar teaching methods. Pre-test and post-test assessments measured grammar proficiency across multiple subjects, including Disaster Risk Reduction and Management (DRRM), Science, Mathematics, Health, Information and Communication Technology (ICT), and Home Economics. Findings revealed that students taught through the thematic approach consistently outperformed their counterparts, showing significant gains in grammar skills across nearly all thematic subjects. Grade 6 students demonstrated the most substantial improvement, particularly in ICT and Science, achieving an average post-test score of 87%. Statistical analysis using Mann–Whitney U and Wilcoxon Signed-Rank tests confirmed that the improvements were significant and attributable to the thematic instruction. Notably, DRRM, Science, Health, and ICT exhibited large effect sizes, whereas Home Economics showed minor progress. It is concluded that integrating grammar instruction within thematic content enhances student learning more effectively than conventional methods. This is recommended that the Department of Education develop policy guidelines and teacher training programs to support this approach. Moreover, teachers should incorporate grammar exercises into relevant thematic lessons, while students should participate in interactive activities to reinforce their learning. Parents are also encouraged to support the use of grammar in daily contexts. Future research should investigate the long-term impacts and effectiveness of this approach in other subjects and grade levels.
Petilo et al. (Sat,) studied this question.