But I know for sure that most of us do want to trust our co-workers, friends, and institutions.

FORBES: I Don't Trust You. Now What?

But what I do know for sure is that by subsidizing the marriage of Bear Stearns and JP Morgan, the government has removed some of the loss from the profit and loss system.

NPR: Does Bear Stearns Bailout Set a Bad Precedent?

But here is what I know for sure.

WHITEHOUSE: Remarks by the First Lady at a Campaign Event -- Reno, NV

But I don't know for sure.

WHITEHOUSE: Press Briefing

Dr. NIEDERDEPPE: Well, I think - we don't know for sure, but I think there are at least three things that may be going on here.

NPR: Confronting Misconceptions About Cancer Prevention

I'm pretty sure I didn't hit anybody, but I'm not gonna say that because I don't know for sure.

CNN: Army tapes reveal motive in Iraq prisoner killings

But seeing their bill and our bill, I know one thing for sure -- we'll have a great bill when we put them together.

CNN: Pelosi asks to see better way than public option

"I don't know whether it has caught me out but, for sure, experience is always an advantage, " said Hamilton.

BBC: Hamilton defiant over title race

Ms. SOFIA TOITEE (Shopkeeper, Saint-Denis): (Through translator) It's better now for sure, but for how long I don't know.

NPR: Violence Overshadows Upcoming French Elections