Artificial intelligence (AI) is increasingly influencing English as a Second Language (ESL) education for Filipino students. This study investigates the effectiveness of Chai, an AI-powered chatbot, integrated into a flipped classroom model, for enhancing students’ prepositional usage. Employing an exploratory sequential mixed-methods design, 70 freshman students were randomly assigned to experimental (Chai Bot/flipped classroom) and control (traditional instruction) groups. The quantitative results indicated that…