Wade claimed he did not know when exactly he would have to leave, nor did he know how long for.

韦德承认他也不知道什么时候会离开，也不知道要花多久。

youdao

It has set us back in so many respects that I'm not sure how long it will take for us to catch up.

我们在很多方面都被延误了，不知道需要多久才能赶上。

《柯林斯英汉双解大词典》

How long did you trek for?

你长途跋涉了多长时间？

youdao

The Serbian president said there will be an investigation into how Mr.Mladic avoided arrest for so long.

VOA: special.2011.05.28

How it ends up in the long run for the Dutch is that the Dutch cease to be a great power.

荷兰长远之后的下场,便是荷兰国力日衰,风光不再

耶鲁公开课 - 欧洲文明课程节选

I'm going to live here for, who knows how long. Quite a long time.

我打算定居在这儿，不知道多久。会是相当长一段时间。

追忆艾米 - SpeakingMax英语口语达人

"If I wanted to leave he would ask me where I was going, why, and how long for, " she said.

BBC: Child fire deaths: Michael Philpott 'hit mistress'

The question is how long for the melting to catch up.

FORBES: Why Most Forbes Readers Know More About Global Warming than Most Climate Scientists

But in the longer term, students and their parents are likely to think a lot harder about whether to study full time or part-time, how long for, in what subject and where.

ECONOMIST: Education economics