to kill a pig as a lesson to the children (idiom) / parents must teach by example
借镜
jiè jìng
(Tw) to draw on (others' experience) / to learn from (how others do things) / lesson to be learned (by observing others)
前车之覆，后车之鉴
qián chē zhī fù , hòu chē zhī jiàn
lit. the cart in front overturns, a warning to the following cart (idiom) / fig. draw lesson from the failure of one's predecessor / learn from past mistake / once bitten twice shy
lit. warning to the following cart (idiom) / don't follow the track of an overturned cart / fig. draw lesson from the failure of one's predecessor / learn from past mistake / once bitten twice shy
拖堂
tuō táng
to drag out a lesson / to insist on extending class after the bell
给你点颜色看看
gěi nǐ diǎn yán sè kàn kan
(I'll) teach you a lesson / put you in your place
长记性
zhǎng jì xing
(coll.) to learn one's lesson / to have enough brains to learn from one's mistakes
上一次当，学一次乖
shàng yī cì dàng , xué yī cì guāi
to take sth as a lesson for next time (idiom) / once bitten, twice shy
温理
wēn lǐ
to review (a lesson etc) / to bring back to one's mind
kè