We're going to the movies. Will you join us?
I'm very sorry I can't.
Why not?
I'm afraid I have some business to attend to.
Then would you like to have lunch with us?
I'd love to but I have to help John with his math problems right now.
Would you like me to give you a lift?
No, thanks. His home is not far and I can walk there.
Come on. It's no trouble at all.
Ok, thank you.