It looked to me like Karimcha knows English well and is looking to fill certain gaps, so why not answer his question? It's better than saying, 'They're basically just the same, it's not that important, foreign speakers shouldn't waste their time trying to understand such niceties, they'll only get all confused.' Exceptions are part of language, of course, but it would be mighty hard to find situations where both are equally correct. energetic, but the fact remains that it is 'absolutely' incorrect to imply that the two are interchangeable or that the difference depends merely on style. I'm sure, Felicity, that you wouldn't say, 'Have you seen Psycho last night?') Did you see it?' (Simple past is the only choice because that particular screening is over. In my opinion 'Did you ever see Psycho?' is substandard English.) Have you ever seen it?' ('Have you ever' is a special construction that embraces a person's whole life experience, travel, work, activities, up to the present, therefore pres. Have you seen it yet?' (There is the possibility of going today or tomorrow, so pres. ' Psycho is playing at the Bijou this week. 'Have you seen Psycho?' As opposed to 'Did you see Psycho?' I think my other examples are clear, but I could add for further clarity: We all learn that the simple past refers to the past and the present perfect implies a connection to the present. Depending on the given situation, every native speaker (including Felicity!) will automatically use one or the other without having to think. The choice between simple past and present perfect in Karimcha's example is indeed a nuance but a crucial and interesting one.

Did you do your homework