If you say that something is certain to happen, you mean that it will definitely happen. However, the scheme is certain to meet opposition from fishermen's leaders Brazil need to beat Uruguay to be certain of a place in the finals The Prime Minister is heading for certain defeat if he forces a vote Victory looked certain
If you make certain that something is the way you want or expect it to be, you take action to ensure that it is. Firstly, they must make certain that their pension needs are adequately catered for = make sure
If you say that something is certain, you firmly believe that it is true, or have definite knowledge about it. One thing is certain, both have the utmost respect for each other It is certain that Rodney arrived the previous day
If you are certain about something, you firmly believe it is true and have no doubt about it. If you are not certain about something, you do not have definite knowledge about it. She's absolutely certain she's going to make it in the world We are not certain whether the appendix had already burst or not It wasn't a balloon -- I'm certain of that. = sure
If you know something for certain, you have no doubt at all about it. Hill had to find out for certain