1. It's on me. (= I'll buy you a drink)
2. I'd like to make a toast. (= I'd like to honor a person/event/idea)
3. Here's to... (your health / the New Year / our success)!
4. Another round of drinks, please.
5. Put it on my tab. (tab = bill to pay later, before you leave)
6. He's a bit tipsy. (= a little bit drunk)
7. He's completely sloshed/wasted/plastered. (= completely drunk)
8. She's trying to drown her sorrows. (= drinking alcohol for relief from pain/sadness)
9. I'm the designated driver. (= I'm not drinking alcohol because I will drive other people home later)
10. I had a hangover. / I was hung over. (= the bad feeling you have the morning after drinking too much)