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.

Give me a fucking reason,
to not smash your head this very INSTANT.
Money Heist Season 1, Episode 12

...with a cup
of Swiss Miss INSTANT cocoa.
The Big Bang Theory Season 3, Episode 15

- Kurt, put him down this INSTANT.
- He started it.
The Big Bang Theory Season 1, Episode 6

Since I decided that I can't stand to look at
any of my handmaidens for another INSTANT.
Game of Thrones Season 2, Episode 7

All over in an INSTANT.
Game of Thrones Season 6, Episode 8