However did you know that?

你到底是怎样知道那件事的？

However did you make such a mistake?

你怎么会犯这样的错？

However hard you shout, Granny won't be able to hear you.

不管你叫得多响，奶奶都听不到你的声音。

He tried his best to solve the problem, however difficult it was.

不管问题有多难，他都会尽力解决。

The composition is all right; there's room for improvement, however.

这篇作文不错，不过还有改进的余地。

Sailing in rough weather can be very unpleasant. However, we found it exciting.

天气不好的时候航行很可能不畅快。然而，我们却觉得很刺激。

His first response was to say no. Later, however, he changed his mind.

他最初的反应是不同意，但是，他后来改变了主意。

However I approached the problem, I couldn't find a solution.

不管用什么办法，我都无法解决这个问题。