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.

instead of a MOB of peasants
who've never held pikes in their lives.
Game of Thrones Season 1, Episode 3

What are you doing
leading a MOB of peasants?
Game of Thrones Season 3, Episode 4

Not long ago,
we were attacked by a MOB there.
Game of Thrones Season 3, Episode 1

Once we'd got King Joffrey
safely away from the MOB,
Game of Thrones Season 4, Episode 6

This same MOB
spat at my sister not long ago.
Game of Thrones Season 7, Episode 3