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.

and forgot something very important
in the BOOT, very important.
Money Heist Season 1, Episode 7

Okay. That's it. Let's BOOT it up.
The Big Bang Theory Season 2, Episode 5

From a broken home, to BOOT.
Psychologically speaking...
The Big Bang Theory Season 1, Episode 10

I’m in the BOOT!
Money Heist Season 1, Episode 7

and he'd be damned
if he'd kiss a traitor's BOOT.
Game of Thrones Season 5, Episode 3