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.

The Air Force did it AGAIN!
They're erasing our lives.
The Big Bang Theory Season 10, Episode 23

- Again, no offense--
- Okay, this is ridiculous!
The Big Bang Theory Season 9, Episode 17

Feel like I wanna peel off my own face,
tear it in two and then AGAIN and AGAIN...
The Big Bang Theory Season 6, Episode 21

Otherwise they'll put me in chains AGAIN.
Game of Thrones Season 2, Episode 5

I just think if we're
gonna try dating AGAIN,
The Big Bang Theory Season 5, Episode 14