I am doubtful whether he will come.
I don't know whether you like her or not.
Do you know whether she can speak English?
I don't know whether George will come or not.
I don't know whether I can do it, but I'll try.
You'll have to do it, whether you like it or not.
I didn't know whether to stay here or go to London.
You must decide whether you will go by train or by plane.
I haven't decided yet whether I'll go to college or get a job.