英语 rain英语中的”rain"有许多形态,但我一直不太清楚哪个地方该用哪个．

It's raining.正在下雨（强调现在）
It rains heavly.雨下得很大（强调状态）
It rained yesterday.昨天下了雨
It has rained for three days.已经下了三天雨了
I took an umbrella yesterday,because I thought it would rain.我以为昨天要下雨,所以带了伞（虚拟语气,实际上没有下）
It's a rainy city.这个城市经常下雨(形容词用法)
It's a heavy rain.(名词用法)
现在能想到的就这么多了,用法不是很难.