act up (no object)
MEANING: Misbehave (for people); Not work properly (for machines).
“My Mum had a difficult time. I was always acting up as a child.”
“I guess I’d better get the television repaired. It’s been acting up lately.”
act like (inseparable)
MEANING: Behave in a way that’s like _____ .
“What’s wrong with him? He’s acting like an idiot.”
Note: This phrasal verb is very informal.
act out (object)
1. When you act something out, you perform it or make it into a play.
2. Express your feelings or ideas.
1. “The script itself is well written and well acted out by the cast”
2. “He has become desperate and is acting out his frustration by behaving like an idiot.”