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.

Stay close to her side. Keep her trust.
Game of Thrones Season 2, Episode 4

and then you're gonna blame me
for making you STAY.
The Big Bang Theory Season 10, Episode 22

So if you don't like this Christy,
why are you letting her STAY?
The Big Bang Theory Season 1, Episode 7

- Come on, come on! Get up.
- Stay down, bitch.
The Big Bang Theory Season 1, Episode 15

I cannot STAY.
Vikings Season 1, Episode 6