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.

I said those words
when I tossed a LEECH into the fire,
Game of Thrones Season 4, Episode 3

And you take credit
because you dropped a LEECH into the fire?
Game of Thrones Season 3, Episode 10

Do you know how many HBOs
that LEECH had my mother get him? Seven.
The Big Bang Theory Season 8, Episode 4