A Study this example situation: Tom is looking for his key. He can't find it. He has lost his key. (present perfect) This means that he doesn't have his key now. Ten minutes later: Now Tom has found his key. He has it now. Has he lost his key? No, he has found it. Did he lose his key? Yes, he did. He lost his key (past simple) but now he has found it. (present perfect) The present perfect (somet..