This study investigates the influence of social media and mobile application usage on the mastery of grammar among Grade 10 students, with a sample size of 123 respondents. Using regression analysis, the research examines how the frequency of use and the features of mobile applications and social media impact students' grammar skills. The findings reveal that social media and mobile applications significantly influence grammar mastery. Social media usage positively affects grammar mastery, while mobile application usage has a negative effect. The data further indicates that students engage moderately with mobile applications, exploring app features more frequently than using them for grammar practice. The study also highlights that the frequency of mobile app use varies, suggesting that students may not use these applications consistently for grammar learning. Overall, the research provides insights into how social media and mobile apps affect grammar skills, showing that while both tools influence grammar mastery, their impact depends on usage patterns and the specific nature of the tools involved.