私下里说，我不确定这没有超出他们的理解。

Confidentially, I am not sure that it wasn't above their heads.

《柯林斯英汉双解大词典》

“我不确定人们是否对这件事有很深的了解。”阿布拉菲亚说。

"I'm not really sure that people should read that much into that," Aboulafia said.

youdao

“我不确定，”达琳先生若有所思地说，“我不确定。”

"I wonder," Mr. Darling said thoughtfully, "I wonder."

youdao

I'm not quite sure,because we have to turn to a metaphysical question that we've touched upon before,namely,can souls split?

我不太确定，因为要先提出一个以前说过的,形而上学的问题，就是，灵魂可以分裂么？

耶鲁公开课 - 死亡课程节选

and I don't know how much I've said so far but, yeah, totally different than here,

我不确定我说了多少不同之处，但是总的来说，跟这里有很多不同，

来自爱荷华 - SpeakingMax英语口语达人

If he had all of that,it's not so clear to me that it would be the wrong thing to say that, by golly,this is Napoleon.

如果他都拥有这些，那我就不太确定，这么说是否错误了，天哪，这是拿破仑。

耶鲁公开课 - 死亡课程节选