Meaning/Usage: Disagree; to not be convinced 不同意 不服气

Explanation: This phrase comes from a popular way of getting agreement, which is "buy in." For example, a company director can say, "we need buy in from all the board members to proceed." In this statement, "buy in" is getting agreement. Therefore, if you "don't buy it," then you are not agreeing.

"He said he didn't do it but I don't buy it."
"Their prices are supposed to be better but I don't buy it."
"She said she was sorry but I don't buy it."

A. "So what were you guys arguing about?"
B. "He said some mean things to me the other day."
A. "Did he apologize to you?"
B. "Yes, but I don't buy it."

Other Common Sentences

"I don't believe it."