be sure about something
be sure of something

But he wanted to be sure of his new power.

But she was no longer sure of much about the future.

He'd worked with such things often enough to be sure of them.

I ask the question without being sure of the answer.

Take your time and stop to think if you aren't sure of something.

I'm not really sure of the point you are trying to make.

Not until she was more sure of the things in her life.

I've never been so sure of anything in my life.

As things are these days, no one can be sure of anything.

For nearly a second, I am sure of nothing else.