Rudeness to the old is not proper.
Laughing and joking at a funeral are not proper.
Short trousers are not proper at a dance.
His speech is proper for the occasion.
The nesting instinct is proper to birds.
It is proper that you should ask your father.
Why are you surprised?It's proper that his wife should inherit all his property.
你为何觉得惊奇?他的妻子继承他的全部财产是合理的。
It isn't proper to act like that.
It isn't proper to visit a friend at this late hour.