Recent advancements in artificial intelligence, particularly OpenAI's ChatGPT, have transformed English language learning through Computer-Assisted Language Learning (CALL) tools. This study examined the adoption of ChatGPT among university-level English learners employing the Hedonic Motivation System Adoption Model (HMSAM). An online survey was conducted with 266 valid responses, analyzed using Structural Equation Modelling (SEM) to assess the key factors influencing ChatGPT adoption. According to the findings, the main factors influencing students' inclination to utilize ChatGPT are perceived usefulness, boredom, and a sense of control. These findings highlight important considerations for integrating AI in English education, suggesting that practical AI tools must address both functional and motivational aspects of learning. The study offers insights for educators and developers in designing AI-driven language learning tools that align with students' needs and motivations, potentially shaping the future of English education.