Provide the theme summaries for the following conversation: 

#Person1#: Dear, can you drive me to the clinic?
#Person2#: I'm afraid I can't.
#Person1#: Why?
#Person2#: Well, my car won't start. I don't know what's the matter with it.
#Person1#: Could it be the battery?
#Person2#: No, I don't think it could be. I checked the battery two days ago. It must be other problems.
#Person1#: Well, I suppose it could be the gas.
#Person2#: No, there is plenty of gas. I filled it up yesterday.
#Person1#: Perhaps it's the starter then?
#Person2#: Yes, that's possible.

Summary: 
#Person2#'s car won't start. #Person1# guesses the problems. #Person2# thinks it might be the starter.