1) I don’t know this girl. I have never met her before.
2) “Where is Mother?”-“She has just gone out.”
3) “Don’t you know what the film is about?”-“No, I have not seen it.”
4) Don’t worry about the letter. I have already posted it.
5) “Is he a good teacher?”-“Oh yes, he has helped me a lot.”
6) I know London perfectly well. I have been there several times.
7) I can’t find my umbrella. I think, somebody has taken it by mistake.
8) “Do you speak Spanish?”-“No, I have never studied it.”
9) “Do you know where they have gone?”-“No,I don`t. They have sold their house and have not left their new address.”