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.

- We've met before, you know.
- Have we? Strange, I've forgotten.
Game of Thrones Season 1, Episode 4

seem STRANGE, but, uh,
The Big Bang Theory Season 12, Episode 10

What if I become STRANGE and eccentric?
The Big Bang Theory Season 10, Episode 23

I have to die
in this STRANGE country.
Game of Thrones Season 7, Episode 3

which l find, l don't know, STRANGE.
Breaking Bad Season 4, Episode 8