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.

and the pain's just a program.
Westworld Season 2, Episode 6

I don't mean in my tender heart
it still PAINS me so.
Game of Thrones Season 6, Episode 5

but flippin' PAINS
in the bottom."
The Big Bang Theory Season 5, Episode 19

She went to great PAINS
to point that out to me.
Game of Thrones Season 3, Episode 10