Hmm, I'm not so sure.

噢，我不是很确定。

youdao

Mmm, I'm not so sure that's a good idea.

嗯，我不知道这想法行不行。

《牛津词典》

Mm, I'm not so sure.

嗯，我不太肯定。

youdao

But Kurt Volker, former American ambassador to NATO, the North Atlantic Treaty Organization, is not so sure what will happen.

VOA: special.2010.07.24

I don't know about that. I am not so sure." But then, we realized that like when we walk out that door, it's the whole world again. So you get sucked up by your group, by your sort of identity.

我不知道，不是很确定，然后呢，我们就意识到走出那个大门，又是一个完整的世界，所以你就会,被你的团体，你的身份所束缚。

普林斯顿公开课 - 人性课程节选

So my walk is, it's not confident and I'm not sure if I'm strong in my step yet.

所以我的走姿不是特别自信，担心步伐会不稳。

I wonder if 实战 - SpeakingMax英语口语达人

But the opposition Conservatives are not so sure the approach can work long term.

BBC: Could 'The Sunderland Way' prevent council job cuts?

The only problem is that I'm not so sure how to work the built-in DVD player.

WSJ: Dan Zevin: Driving in the Car With Dad

However, other cancer specialists are not so sure that the technique could be without potential pitfalls.

BBC: Fertility hope for cancer women