Is that you, John?
Yes, speaking.
Tell Mary we'll be late for dinner this evening.
I'm afraid I don't understand.
Hasn't Mary told you?
She invited Charlotte and me to dinner this evening.
I said I would be at your house at six o'clock, but the boss wants me to do some extra work.
I'll have to stay at the office.
I don't know when I'll finish.
Oh, I see.
I don't think Mary will be very pleased.
I'll ring her if you like.
No, thanks. I'll explain to her.
Don't worry. We'll be there as soon as we can.
I'm sure you will.