The best way to learn proper English is to read news report, and watch news on TV. Watching TV shows is a great way to learn casual English, slang words, understand culture reference and humor. If you have already watched these shows then you may recall the words used in the following dialogs.

Ooh, are-are you gonna
write it on a NAPKIN
The Big Bang Theory Season 12, Episode 17

- That's actually my NAPKIN.
- Oh, this is a nightmare.
The Big Bang Theory Season 4, Episode 23

- Could you grab me another NAPKIN?
- Sure.
The Big Bang Theory Season 3, Episode 10

Yeah, he's writing it on
a NAPKIN like in the movies.
The Big Bang Theory Season 12, Episode 17

Can I just see
what he wrote on the NAPKIN?
The Big Bang Theory Season 12, Episode 17