Have you ever seen the rain coming down on a sunny day?

Present Perfect is a bugger innit? You'll just have to knuckle down and learn the blasted thing. There are many subtleties in the use, for example, why is it okay to say: "Have you ever seen (the film) 'Gone With the Wind'?" but sounds odd if you say, "Have you ever seen 'Shrek 2'?"

It's because ever carries the meaning of sometime in ALL of your life, so whereas Gone with the Wind has probably existed in most of the lifetime of the person you are asking, Shrek 2 was released only very recently. With this in mind then, would it be odd to ask someone born in, let's say the 1920's (Gone with the Wind was made in 1939), "Have you ever seen 'Gone with the Wind'?"?

BEWARE the Jabberwock, my son! Translate literally word for word, He has gone to London into Portuguese and you get Ele tem ido para Londres, which actually means He has been going to London (a lot recently). He has gone... would have to be translated into the Portuguese equivalent of Past Simple: He went...

Hmmm, now the difficulty, then what's the difference between He has gone... and He went... ? The present perfect would suggest that the action was recent or 'new news', with no determined time (*He has gone ... yesterday. Is wrong), it's much more common in British English at least. He went... would be a determined time, stated or implicit, which, and I COULD BE WRONG, I believe is much more common in American English. I hear a lot on Hollywood films: Did you see (Gone with the Wind)? or Did you finish yet?, yet in this question carries the meaning of from sometime in the past until now, so this would imply the use of present perfect, is it wrong then? Nope, it's Linguistic Variation!