I don't know for sure.

我不能肯定。

youdao

I don't know for sure. You can ask others, please.

我不是太清楚，请你问一下别人吧。

youdao

I don't know for sure because I don't look ahead in the scripts.

没提前看剧本所以我也不是很清楚。

youdao

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 I don't know for sure.

WHITEHOUSE: Press Briefing

Again, I don't want to give you an itemized list of topics that were discussed because I don't have that list to read from for you and I don't wan to say that something was discussed if I don't know for sure that it was.

WHITEHOUSE: Press Briefing