I don't really know. I'm just guessing.

我并不知道，我只是猜测。

《牛津词典》

I've only been here a couple of weeks and I don't really know the set-up.

我刚来几个星期，对这里的组织情况不大了解。

《牛津词典》

The general topic I chose is aesthetics, but that's as far as I've got I don't really know where to go from there.

我选择的主题是美学，但就我所知，我真的不知道该怎么做。

youdao

Their house crashed. As for everyone else, I really don't know what's going on.

VOA: special.2010.02.01

But for me, I like to look at something and just say, "I like this. I don't really know why though."

但对我来说，我喜欢看着某个东西，然后说，“我喜欢这个。但我也不知道为什么。”

关于现代美术 - SpeakingMax英语口语达人

This is exactly where I don't really know the details, but I take it it's something like: because of whatever the original input was, eventually the blood's no longer circulating and oxygen isn't making its way around the body.

事实上我对这方面不是很了解,我只能认为是,不论最初的死亡原因是什么,最后血液不再流动,氧气不能输送到全身

耶鲁公开课 - 死亡课程节选

"I don't really know what he's thinking but I think something can be done, " said Eoin Bradley.

BBC: Eoin Bradley wants brother Paddy back in Derry squad

Beyond eBay, I don't really know how many options you have other than if you're within your return time.

NPR: Tips for Fighting Technology Overload

And so I feel like - I don't really know where I'm from.

NPR: Another Look at the Immigration Debate