Cách sử dụng
"Sell somebody down the river" means to betray someone's trust or deceive them for one's own benefit. The expression comes from a time when African American slaves were sold from the Northern part of the United States to the Southern part (known as being "sold down the river") and separated from their families. Today, the expression can be used in any situation where someone is being betrayed or taken advantage of by someone they trust. For example, if a coworker promises to help you with a project but instead takes credit for all of the work you did, you could say they "sold you down the river."