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.

Not until I met the king
of the GRIM, bearded, stinking barbarians.
Game of Thrones Season 3, Episode 2

Don't look so GRIM, Jon Snow.
Game of Thrones Season 3, Episode 1

Come, Maester, don't look so GRIM.
Game of Thrones Season 2, Episode 7

Grim, bearded,
Game of Thrones Season 3, Episode 2

I'm sure it's very GRIM
after King's Landing.
Game of Thrones Season 1, Episode 1