to cast pearls before swine
[cast|throw] {one's} pearls before swine
to cast pearls before swine
01
对牛弹琴, 好心白费
to do good things and waste valuable resources for ungrateful people
idiom
例子
I tried explaining the importance of saving money to my friend who always spends impulsively, but it felt like I was casting pearls before swine.
给他们买贵重礼物就是好心白费。



























