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.

If I was your size,
I'd be king of the fucking WORLD.
Game of Thrones Season 4, Episode 4

And extra Dramamine? You remember
what happened on It's a Small World.
The Big Bang Theory Season 6, Episode 24

only to find such chaos in the WORLD,
I can only imagine...
Game of Thrones Season 7, Episode 4

And yet the WORLD belongs to them.
Game of Thrones Season 3, Episode 4

darkness will fall heavy on the WORLD.
Game of Thrones Season 2, Episode 1