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.

Robb has SURPRISED them all
with his skills in battle,
Game of Thrones Season 2, Episode 4

I'm SURPRISED you would do that.
The Big Bang Theory Season 9, Episode 20

I shouldn't be SURPRISED.
I suppose she's your kind of woman.
Game of Thrones Season 7, Episode 7

Then why are you SURPRISED
she didn't tell you?
The Big Bang Theory Season 4, Episode 22

Yeah, I'm just a little SURPRISED
you didn't tell me.
The Big Bang Theory Season 2, Episode 23