1.save for a rainy day 未雨绸缪
We save money for a rainy day.
我们存点钱算是未雨绸缪。
2.It never rains but it pours 祸不单行
I just got sacked and my wife left me! So it never rains but it pours!
我刚被解雇,妻子又离开了我,真是祸不单行啊!
3.head in the cloud 好高骛远
You can't always have your head in the cloud.You need to be down-to-earth.
你不能总是那么好高骛远,要脚踏实地一些。
4.chase rainbows 做白日梦
Chasing rainbows won't get you anywhere.
做白日梦不会对你有任何帮助。