You're meeting him tomorrow? Let me know what transpires.

你明天和他见面吗？把见面的情况告诉我。

《牛津词典》

All the other candidates are no match for him! Let me know how your summer's going! I'll miss you guys while I'm working here in the library.

其他所有的候选人都不是他的对手！让我知道你的暑假过得怎么样！我在图书馆工作的时候会想念你们的。

youdao

If anything happens to him, let me know at once.

如果他出了什么事，请立刻通知我。

《新英汉大辞典》

He often phones me and tells me to let him know if I want to go somewhere and he will come with me.

BBC: Somali student Mukhtar Ahmed Osman in Moscow

Let me tell you what I know about him.

CNN: Clinton: Time again to choose a more perfect union

It is an honor to call him my friend, and let me be very clear, I know that Sen.

NPR: Next for Clinton: Vice President? Senate? Governor?