It was raining cats and dogs.
下着倾盆大雨。

It rained cats and dogs this morning.
今天上午下着倾盆大雨。
We were about to get home,when it began to rain cats and dogs.
我们快要到家了，这时下起了倾盆大雨。

A:Hi,Cindy.I thought I'd missed you.
嗨，辛迪。我以为我错过你了。
B:I am very sorry,Hans.Thank you for waiting for me.You must have been here for a long time already.
恩，真对不起，汉斯。谢谢你等我。你一定在这儿等很久了。
A:It's all right.
没关系。
B:I was caught in the heavy rain,or I would have come earlier.I am sorry I kept you waiting.
我赶上下雨了，不然我会早点到。很抱歉，让你久等了。
A:I was in a comfortable place,so really,it's no problem.I am happy to see you.Did the rain hold you up long?
我等的地方很舒适，真的，没关系的。我很高兴见到你。你被雨妨碍了很长时间吗？
B:Yes.When I came out of the subway,it was raining cats and dogs.And I forgot my umbrella.So I had to wait for the rain to let up.
是的，我从地铁站一出来，就下着倾盆大雨。而我忘了带伞，所以只好等雨小一点。
A:I totally understand.
我完全理解。