"why buy a cow when you can get milk for free" in Chinese (Simplified)
Definition
这个表达意思是，如果你已经能免费得到好处，就没必要去花钱或承担更大的责任。常用在感情或大额购买的情境中。
Usage Notes (Chinese (Simplified))
这是一个非正式、略显过时的表达，常用于暗指同居却不结婚，也可以用在买东西时。讲感情时容易被认为有性别歧视的意味，请注意场合。
Examples
Some people say, 'why buy a cow when you can get milk for free' to explain not getting married.
有些人用“**既然可以免费得到牛奶，为什么还要买牛？**”来解释为什么不结婚。
The phrase 'why buy a cow when you can get milk for free' can also be used for shopping.
“**既然可以免费得到牛奶，为什么还要买牛？**”这个说法也适用于购物。
He heard 'why buy a cow when you can get milk for free' from his uncle.
他从叔叔那里听到“**既然可以免费得到牛奶，为什么还要买牛？**”。
A lot of people throw around 'why buy a cow when you can get milk for free' when talking about moving in together before marriage.
很多人谈论婚前同居时都会用“**既然可以免费得到牛奶，为什么还要买牛？**”。
She joked, 'why buy a cow when you can get milk for free', when her friend asked about marriage.
朋友问起婚姻时，她开玩笑说“**既然可以免费得到牛奶，为什么还要买牛？**”。
You know, in today’s world, 'why buy a cow when you can get milk for free' makes sense to a lot of people.
你知道吗，现如今，“**既然可以免费得到牛奶，为什么还要买牛？**”对很多人来说很有道理。