Use the expression "Hey man" at the beginning of a sentence for a few different purposes:
- to greet someone:
A: Hey man.
B: Hey man. What's up?
- to get someone's attention:
Hey man, are you finished with that?
- to correct someone's understanding of what you're thinking:
Hey man, I didn't mean to offend you. I apologize for saying that.
"Hey man" is mostly used by men when talking to other men.