I want him back, but I just don't know how to go about it.

我希望他回来，可我就是不知道怎么去做这件事。

《柯林斯英汉双解大词典》

But I just don't know how to distinguish myself.

但我就是不知道如何让自己与众不同。

youdao

I don't know what a cheque-book is, but I should just love to give my mother one.

我不知道支票簿是什么，但我真想给我妈妈一本。

youdao

I do not know what is happening, not just in Spain, but in Europe and the world."

VOA: standard.2010.06.24

But they don't I don't know, it's just -there isn't enough initiative in the world, not many people do it.

但是他们没有这样做,我不知道,也许只是,主动性不够,没什么人这样做

耶鲁公开课 - 金融市场课程节选

And um, eventually, at first, I was just, you know, sitting in, but then I had to take a licensing exam

一开始我只坐在那里，可是之后还要进行一次许可考试，

广播人员怎么样？ - SpeakingMax英语口语达人

But I just need to know what happened.

FORBES: Pritzker vs Pritzker

But I know that they don't -- but I know they don't want to just offer nothing to the millions of people in America who are in the situation that that woman was in.

WHITEHOUSE: The White House

But most of all, I want to thank all of you for taking the time, not just tonight, but I know so many of you who have been working so hard over the last year or two, or three and a half.

WHITEHOUSE: Remarks by the First Lady at a Campaign Event