3. "What's going on?" can mean two things. It can mean the same as "What is happening?" or it can be an idiom for "Hello."
Ways to use "What's going on?"
- You didn't do any of your homework. What's going on?
- There is too much noise from this room. What's going on?
- You are fighting with your brother/sister. Why? What's going on?
"What's going on?", "What's up?", "How are you?", "Howdy" - these are also ways of saying hello in English