Recently, Bhutan has undertaken a major educational shift by benchmarking its national curriculum to the Cambridge International Standards. This transformative step demands teaching and learning practices that meet the international criteria. English, as one of the core subjects, plays an important role in ensuring that students acquire necessary skills to meet the global standards. In the secondary English curriculum, students are required to write argumentative essays, which help develop critical thinking, reasoning, refutation, and communication skills essential for global competence. The present study employed an action research approach to enhance students’ argumentative writing skills through debate and collaboration for grade XII students. Pre-test and post-tests for argumentative essay writing were administered. An online survey was also conducted after the interventions to collect the qualitative data. The results of data analysis using descriptive statistics revealed a statistically significant difference between the mean, median and standard deviation scores of the pre-test and post-tests, indicating the positive influence of the two interventions in enhancing students’ argumentative writing skills. Based on the findings, this study concluded that debate and collaborative writing are better teaching strategies for enhancing grade XII students’ argumentative writing skills.