***** NOT A TEACHER *****
Are you referring to something like this:
Tom knocks on Mona's door.
Mona (opens door): Hello, Tom. I did not know that you intended to visit me.
Tom: I had nothing to do, so I decided to just drop by and say hello.
Mona: Oh, that's so nice of you. Actually, though, I was just starting to eat dinner when you knocked on my door.
Tom: No problem. Do have your dinner first. I will just wait in the living room until you have finished.
Mona: Would you like to join me for dinner?
Tom: Well, since you asked ...