Кто шарит в Present Perfect и Present simple Хелп плс

1. I don't know this man. I have never met him. 2. Let's go to the cinema . A new film is on.-my friend has already seen it. 3.where is Nick? He has just gone out.4. Don't you know what the story is about?- no , I have not read it.5. Don't worry about the letter. I have already posted it. 6. Is he a good boy?- Oh, yes he has helped me a lot .7. I know Kiev perfectly well. I have been there several times.