Abstrak
This study examines students' mistakes in translating idiomatic idioms among sixth- semester students in the English Department at the University of Borneo Tarakan. This study also explores the variables that cause these errors. This study uses qualitative content analysis techniques and the subjects are students from local A1 and A2 in the sixth semester of the English Education Department, University of Borneo Tarakan. This study employs qualitative content analysis approaches, focusing on students from local A1 and A2 in their sixth semester, majoring in English Education at the University of Borneo Tarakan. Data collection was executed via document analysis and interviews. The results of the study found that students faced many challenges in interpreting idiomatic phrases, including linguistic knowledge, cultural differences, and style constraints. This occurs as students struggle to identify the most analogous source language and to derive a meaning that aligns with the idiomatic expression. Numerous challenges arise from factors such as students' unfamiliarity with idiomatic expressions, cultural disparities between English and Indonesian, the infrequent application of these expressions in daily communication or writing, and the intricacies associated with interpreting idiomatic phrases. Finally, this study encourages lecturers and students to investigate language through vocabulary and linguistic phrases, particularly idioms, and to apply them in daily practice, both written and spoken, in and out of the classroom.