Cách sử dụng
The expression "act up" is used to describe when something or someone doesn't work properly or is misbehaving. For example, if a machine is not working as it should, you could say "the machine is acting up". Similarly, if a child is misbehaving, you could say "the child is acting up". It can also refer to a situation becoming chaotic or out of control, such as a party that suddenly gets rowdy.