Are you sure about this decision?

I double-checked just to be sure.

Sure enough, it started raining just as we left the house.

Using a fire extinguisher is a sure-fire way to put out a small fire.

I'm not sure

He is always sure of oneself when making decisions.

The criminal is sure to do time for robbing the store.

Please make sure to include the f.b. with the shipment.

There is only one surefire way to lose weight: eat less and exercise more.

He navigated the treacherous mountain path with surefooted grace.