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.

Trailing BADLY, Wolowitz needs a strike...
The Big Bang Theory Season 2, Episode 11

after it went
so BADLY with Penny.
The Big Bang Theory Season 5, Episode 13

I need him very, very BADLY.
Breaking Bad Season 2, Episode 2

One day that's
gonna end very BADLY.
The Big Bang Theory Season 12, Episode 23

Not BADLY injured.
Money Heist Season 1, Episode 13