He was beginning to doubt whether it would be short after all.

Now was he beginning to doubt even his own God?

And sometimes I begin to doubt if there are stories.

But after only the first day's travel, even he began to doubt the decision.

You move forward when even I begin to doubt myself.

Though I am beginning to doubt that story as well.

Over the years, I began to doubt that he ever would.

For the first time I am beginning to doubt whether it ever really happened.

By this point, I began to doubt everything he said.

Players are beginning to doubt if he will ever be a leader.