[Phrasal Verb] ACT UP - Learn to Manage Unruly Behavior: A Guide
Act up
/ˈækt ʌp/
Behave poorly or strangely.
The phrasal verb "act up" is used to describe someone or something that is behaving abnormally or causing trouble. For example, if a normally well-behaved child starts throwing tantrums, you might say the child is acting up. Similarly, it can be used when a device or machine starts malfunctioning, indicating it is not operating as it should.
Example Sentences
Anna's car started to act up again; it wouldn't start this morning.
The car was malfunctioning and wouldn't start.
My old laptop acted up during the presentation.
During the middle of a presentation, the old laptop started having performance issues.
Whenever she is about to go on stage, her nerves act up, making it harder to perform.
When she's preparing to perform on stage, she experiences increased anxiety, which adversely affects her ability to perform.