This study elucidates considerations surrounding university students’ use of artificial intelligence (AI) in their coursework, and its impact on online language learning and assessment. This exploration is based on students’ personal experiences and perceptions. To investigate the students’ use of generative AI, an open-ended questionnaire, consisting of optional questions, was developed. A total of 54 students from diverse undergraduate fields of study, who were enrolled in online General English, English for Academic Purposes or Academic Writing courses, provided responses to the open-ended questions. The data were analysed inductively by two researchers using thematic analysis. The findings suggest that, despite offering numerous potential benefits to student learning, such as facilitating learning and supporting language proficiency, AI language models also raise a variety of challenges and concerns. These include issues related to plagiarism, cheating, assessment and over-reliance on AI.