We shall never have friends if we expect to find them without fault.
欲求完美无缺的朋友必然成为孤家寡人。 

Wet behind the ears.
乳臭未干。 

Whatever you do, do with all your might.
不管做什么，都要一心一意。 

What is learned in the cradle is carried to the grave.
儿时所学，终生难忘。 

What's done cannot be undone.
生米煮成熟饭了。 

What's lost is lost.
失者不可复得。 

What we do willingly is easy.
愿者不难。 

When in Rome, do as the Romans do.
入国问禁，入乡随俗。 

When everybody's somebody then nobody's anybody.
人人都伟大，世间没豪杰。 

When sorrow is asleep, wake it not.
伤心旧事别重提。 

When sorrows come, they come not single spies, but in battalions.
新仇旧恨，齐上心头。 

When the fox preaches, take care of your geese.
黄鼠狼给鸡拜年，没安好心。 

When wine is in truth, wit is out.
酒后吐真言。 

Where there is a will, there is a way.
有志者事竟成。 

Where there is life, there is hope.
留得青山在，不怕没柴烧。