It was raining cats and dogs.
下著傾盆大雨。

It rained cats and dogs this morning.
今天上午下著傾盆大雨。
We were about to get home,when it began to rain cats and dogs.
我們快要到家了，這時下起了傾盆大雨。

A:Hi,Cindy.I thought I'd missed you.
嗨，辛迪。我以為我錯過你了。
B:I am very sorry,Hans.Thank you for waiting for me.You must have been here for a long time already.
恩，真對不起，漢斯。謝謝你等我。你一定在這兒等很久了。
A:It's all right.
沒關系。
B:I was caught in the heavy rain,or I would have come earlier.I am sorry I kept you waiting.
我趕上下雨了，不然我會早點到。很抱歉，讓你久等了。
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?
我等的地方很舒適，真的，沒關系的。我很高興見到你。你被雨妨礙了很長時間嗎？
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，我從地鐵站一出來，就下著傾盆大雨。而我忘了帶傘，所以只好等雨小一點。
A:I totally understand.
我完全理解。