"Did you see...", suggests that you thought the person was going to see it but you're not sure if they watched it or not. So you're referring to a particular time in the past which has now ended. It could also be used if the film was on at the cinema but it isn't anymore. Past simple would be used here because the situation cannot change as the period of time you are referring to has ended. "Have you seen ...", just means did you watch it at any time in your life (up to the present). We use present perfect when a situation can change in the future (because the time period we are referring to hasn't finished). Compare these two examples: - 'Did you drink any coffee yesterday?' - 'I drank 3 cups.' [the number '3' cannot change] - 'Have you drunk any coffee today?' - 'I have drunk 2 cups.' [the number '2' can change]

See if you can make out the different in the following sentences: Did you see the comets last night? * have you seen Robert by any chance today? (You are just walking in your company and a colleague of yours ask you whereabouts of Robert.) * Have you seen the new episode of ' The Walking Dead', It was aired yesterday on amc. * Did you pass your exam? * Have you finished your exams? Put it simply, 'have' implies a sort of connection with the present time while past simple lies in the past with no connection to the present. If you did not managed to see the comets then you will not be able to see them anymore because this action was ended in the past, however, the new episode of walking dead is still downloadable or there is a repeat for that on TV. So in the latter example, you are expected to experience the action sometime around in the future.