I am doubtful about the success of this project.
I’m doubtful about his story.
They were doubtful about the offer.
They are doubtful about investing now.
He was doubtful about joining the plan.
She became doubtful about trusting him.
We’re doubtful about finishing this today.
He’s doubtful about the schedule working out.
She is doubtful about getting the visa on time.
We’re doubtful about traveling during the storm.
I’m doubtful about this information being accurate.
