1. To say hello to someone.
"Mate! How are you?!"
2. To reference friends.
3. To express excitement for someone.
4. To express disbelief.
5. To replace the phrase "here's the thing" or "let me tell you", for when you're about to drop a truth bomb.
6. To warn someone that you're annoyed with them.
7. To tell someone they need to chill.
8. To replace the phrase "this guy", in an affectionate manner.
"Old mate over here needs to get it together."
9. To replace the words "bitch" or "dude".
10. To accentuate a stern conversation.
11. To disagree with someone.
12. To address someone when you don't know/can't remember their name.
13. To verbally shake your head at someone.
"Mate. Mate, mate mate mate, maaaaate."