This article discusses the challenges of learning and teaching English idioms, especially when translating them into Vietnamese. Idioms often carry figurative meanings and cultural nuances, which present difficulties due to differences in context and structure between the two languages. The article emphasizes the importance of dynamic equivalence in translation, which helps preserve the meaning and emotional impact of idioms. Additionally, context and cultural sensitivity play vital roles in understanding and accurately translating idioms. Teachers should use methods like storytelling, dialogues, and visuals to help students grasp idiomatic expressions more easily.