ISSN: 2782-893X
eISSN: 2799-0664
ISSN: 2782- 893X
—— This study examined the effectiveness of AI-assisted grammar checking in improving subject–verb–object (SVO) agreement proficiency among English major students. Employing a quasi-experimental pre-test–post-test research design, the study involved 40 first-year Bachelor of Secondary Education major in English students from a selected higher education institution in the Philippines. The intervention utilized an AI-assisted grammar checking tool integrated into structured grammar writing activities for six weeks. Data were gathered using a researcherdeveloped grammar proficiency test, writing performance tasks, and student engagement questionnaires validated by language experts. Reliability testing yielded a Cronbach’s alpha coefficient of 0.89, indicating high internal consistency. Statistical analyses using SPSS included mean, standard deviation, paired sample t-test, independent sample t-test, percentage distribution, and Cohen’s d effect size analysis. Findings revealed that students demonstrated significant improvement in SVO agreement proficiency after exposure to AI-assisted grammar checking activities. Results further indicated increased learner engagement, improved grammatical accuracy, and heightened awareness of sentence construction. The intervention showed a large effect size, suggesting that AI-assisted grammar tools significantly contributed to learners’ writing performance and grammatical competence. Despite technological benefits, challenges related to overdependence on automated correction and digital accessibility were also identified. The study concludes that AI-assisted grammar checking can serve as an effective supplementary instructional strategy for grammar instruction and writing development in higher education language classrooms. Keywords: artificial intelligence, grammar instruction, subject–verb–object agreement, educational technology, writing proficiency, AI-assisted learning, English language teaching, quasi-experimental research