礼貌

Children must learn manners.

Mind your manners.

out of politeness/courtesy; for politeness

professional courtesy

treat one's guests with courtesy; show civility to one's guests

courteous young man

have good manners; be courteous/polite

cultivate good manners

have no manners; be impolite; lack civility

mind one's manners

observe the proprieties; observe the rules of politeness

have no manners; be impolite

show courtesy

It is impolite/rude to point at people.

It's bad manners to eat with your mouth open./It's rude to eat with your mouth open.

impolite language/behaviour

polite language/behaviour

be impolite