for a certainty

基本解释

And, if we know it for a certainty, how do we know it?
如果我們確實知道這些情況，我們又是如何得知的呢？
I know for a certainty that the company has been bought up.
我確實知道公司已經被人收購了。
I was obliged to admit that I did know it for a certainty, and I said to myself, 'Pip, what a fool you are!
可是我又不得不承認她一定會帶給我不幸。我在心中暗暗責備自己：“皮普，你是多麽愚蠢啊！”

At any rate, I don't know for certainty that I'm a harder grader, but I believe that it's the case based on reactions I get when I give the speech that I'm about to give.
不琯怎麽，雖然不是特確定我評分嚴格，但相信應該就是這樣,根據我每次說這些話時得到的反應來說。
耶魯公開課 - 死亡課程節選

Better to wait for a resolution, certainty is better than uncertainty.
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For it is a certainty that no matter what they do, some people will claim that they were too aggressive and others will claim that they were not aggressive enough.
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He has the endorsement of Mr Riordan and of the Los Angeles Times, and his charisma and energy make up for a lack of certainty about how he would run the city.
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