I should let you know first that I am a policeman.

我首先应该让你知道我是一名警察。

youdao

Just thought I should let you know someone's watching.

我只是觉得有必要让你知道，有人在盯着你。

youdao

I'll let you know when I do.In the meantime, we should be moving along.

我知道了以后告诉你。现在，我们要走了。

youdao

As I say, the syllabuses should be accessible on the Classsv2 server; however, I've had problems with that in the past and you should please let me know if it's not.

你们可以在2号课程服务器上下载大纲;,不过我曾经下载不了,如果现在还不能下的话，一定要告诉我。

耶鲁公开课 - 现代诗歌课程节选

But if you are one of those who care whether the chancellor cut the deficit in 2012-13 - I thought I should let you know that the latest official version of history says he didn't.

BBC: Borrowing: is it up or is it down?