Are you sure?
Are you sure about that?
Are you sure of what you said?
Are you sure that he is not coming?
I have had so many problems with my new car.It's driving me crazy.
Are you sure you don't to buy a new one.
How can I?I already spent a lot of money on this.
I guess you'll spending a lot of money on repairs then.
I guess so. Unless you want to buy a car.
No thanks,I don't think I want to buy your car.It has too many problems.
I don't blame you.It's a piece of junk.