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.

So, you're here to strike a BARGAIN?
Game of Thrones Season 4, Episode 10

I'll stay with Drogo until he fulfills his end
of the BARGAIN and I have my crown.
Game of Thrones Season 1, Episode 2

But for you, it's the usual,
17 percent and that's a BARGAIN.
Breaking Bad Season 3, Episode 9

- This is not part of our BARGAIN.
- Fine, Jaqen H'ghar.
Game of Thrones Season 2, Episode 8

You want to strike a BARGAIN with me?
Here's the BARGAIN.
Game of Thrones Season 4, Episode 10