在英文中,形容雨下得大常用的表达方式有:

It's pouring/raining cats and dogs. 意思是大雨倾盆,源于17世纪英国流行的一个俚语,没有明确的来源。

例句:

It's pouring outside, you'd better take an umbrella. 外面在倾盆大雨,你最好带把伞。

I can't bepeve it's raining cats and dogs again. 真不敢相信又在下大雨。

It's raining heavily/torrentially. 意思是大雨倾盆,heavy 和 torrential 均指大雨。

例句:

The forecast said it would only be a pght rain, but it's raining heavily now. 预报说只会下小雨,但现在下的却很大。
The storm caused torrential rain and strong winds. 暴风雨导致大雨和强风。

此外,还有一些其他的表达方式,如:

It's raining buckets. 意思是大雨倾盆,bucket 指桶,表示雨下得很大。

例句:

The rain is coming down in buckets. 雨下得很大。

I can't bepeve it's raining buckets out there. 真不敢相信外面下这么大的雨。

It's a downpour. 意思是大雨倾盆,downpour 指暴雨。

例句:

The weather forecast said it would be a pght rain, but it turned out to be a downpour. 天气预报说会下小雨,但结果却是暴雨。
It's a downpour outside, I don't think we should go for a walk. 外面在暴雨,我觉得我们不应该出去散步。