Senator RICHARD LUGAR (Republican, Indiana): I'm not certain what complete victory means.

NPR: Defining 'Complete Victory' in Iraq

I'm not certain that mega rock stardom was really for him.

BBC: Peter Banks: Original Yes guitarist dies aged 65

So I mean I'm not all certain that even if the trade union leaders instructed their members to go to work this week they would actually do so.

BBC: News Online

Dr. Kleissl praised Aidan's work, but added that even if Aidan had measured the right variables, "I'm certain that he will not find that his arrangement is better, " he said.

WSJ: A Youngster's Bright Idea Is Something New Under the Sun; Scientist Is 13-Year-Old Aidan Dwyer

So I'm certain that we're not over it as a country.

NPR: Assessing the Impact of Assassinations

And I'm certain that Mr. Sensenbrenner would not intentionally mislead the Senate, that his error is one of inadvertence.

CNN: Transcript: White House Counsel Ruff's opening statement

Not only am I fairly certain of this, I'd guarantee it (and I'm not in the habit of guaranteeing many things).

FORBES: Magazine Article

And I'm almost certain that the military strike is not going to achieve anything.

NPR: The Nuclear Debate from Iran's Viewpoint

"I'm not saying technology is junk food, but you learn to live without certain things in life, " says Zschappel, who trimmed 20 pounds this year by swearing off snacks and soft drinks.

FORBES: Lynch Redux

That's like -- is that three years ago? (Laughter.) I did not have as much gray hair back then. (Laughter.) That I'm certain of.

WHITEHOUSE: Town Hall Meeting on the Economy