Cách sử dụng
The phrase "foul up" means to make a mistake or to cause a problem. It is often used in informal situations to describe something going wrong. For example, if someone accidentally deletes an important file, they might say "I really fouled that up." It can also be used to describe a situation that is messy or confusing, such as "The traffic was really fouled up this morning." This expression is commonly used in spoken English, but may not be appropriate in formal writing.