Final answer:
'When are you leaving?' is a question about someone's departure plans.
Step-by-step explanation:
'When are you leaving?' is a question about someone's departure. In English, it is a common way to ask about someone's plans to depart from a place or situation. The question can be used in various contexts, such as asking about travel plans, work schedules, or personal commitments. For example, 'I'm leaving for vacation next week' or 'I'm leaving the office at 5:00 PM today.'