The adoption of English as a Medium of Instruction (EMI) in Turkish universities has heightened the necessity for advanced English proficiency among students. Many intermediate-level English learners face stagnation, known as the intermediate plateau, hindering their progress and affecting academic performance. This study explores the use of Artificial Intelligence (AI) to personalize English language learning and overcome this plateau among intermediate-level students at an EMI university in Turkey. A mixed-methods research design was employed, involving 20 intermediate-level EFL students who used an AI powered language learning platform over one semester. Quantitative data were collected through pre- and post-intervention proficiency tests and engagement surveys, while qualitative data were obtained via interviews, focus groups, and classroom observations. Findings indicated significant improvements in language proficiency across all four skills and increased learner engagement. Students reported positive perceptions of the AI tools, highlighting benefits such as personalized learning, immediate feedback, and enhanced motivation. The study provides evidence-based recommendations for integrating AI into language education and underscores the importance of aligning AI tools with pedagogical objectives. Challenges encountered during implementation are discussed, offering insights for future applications. This research contributes to the literature on AI in language learning and suggests that AI can play a pivotal role in enhancing English proficiency in EMI contexts, ultimately supporting students to surpass the intermediate plateau and achieve greater academic success. [This paper was published in: "EJER Congress 2024 International Eurasian Educational Research Congress Conference Proceedings," edited by Senel Poyrazli, Ani Publishing, 2024, pp. 207-213.]