I certainly know the answer.

我当然知道答案。

youdao

I certainly know that he has come.

我当然知道他来了。

youdao

I certainly know I'll use it when I'm out and about. '.

我肯定我在外出时会带着他。

youdao

Abbas Milani, an analyst at The Hoover Institution, "I certainly know of no time in Iranian history where the democratic discourse, and the social basis of democracy have been as strong."

VOA: standard.2010.06.11

So, if you feel there's not enough math used, I guarantee you that I certainly know enough eventually to snow the whole class, but that's not the point.

如果你觉得我用的数学太少,我可以保证,我知道的数学知识,足以难倒在座的所有人,但这不是重点

耶鲁公开课 - 基础物理课程节选

I don't know if it's the biggest, but it's certainly one of the best collections of stuff

我不知道那是否是最大的，但是绝对是最好的收藏之一。

世界的宝物都聚于此 - SpeakingMax英语口语达人

"I certainly know it's the best round of golf I've ever played, especially under these circumstances, " said the 38-year-old.

BBC: Davis Love weighs up a putt during his final round

"I certainly know a lot of practitioners, who, while being seasoned litigators, don't have a concrete philosophy on where the law should be on these issues, " Copland said.

FORBES: She's Good For Business

Well, if you don't know, I certainly don't know.

WSJ: Keep Your Kids Safe With AT&T