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.

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

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

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

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

A token of a BARGAIN well struck.
Game of Thrones Season 3, Episode 3