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.

The leaves are turning.
There's a bracing CHILL in the air.
The Big Bang Theory Season 2, Episode 6

Chill out? No.
No, I don't CHILL out right now
Breaking Bad Season 5, Episode 11

Chill out? No.
No, I don't CHILL out right now
Breaking Bad Season 5, Episode 11

Just hold on.
Just CHILL.
Breaking Bad Season 2, Episode 5

Of course I am. Removing Joe Chill
as the killer of Batman's parents...
The Big Bang Theory Season 2, Episode 20