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 beg to DIFFER.
- We're at war.
Game of Thrones Season 7, Episode 4

How does it DIFFER
from the money I have?
The Big Bang Theory Season 3, Episode 5

Oh, no, I beg to DIFFER.
The Big Bang Theory Season 2, Episode 4

Accounts DIFFER.
Game of Thrones Season 2, Episode 5

Well, apparently these people and I
DIFFER greatly on the definition of "party."
The Big Bang Theory Season 3, Episode 12