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.

Hell, I'm AMAZED you got this far.
Breaking Bad Season 2, Episode 11

What, really, I’ll be AMAZED?
Money Heist Season 1, Episode 12

Pick a card, put it back,
and prepare to be AMAZED.
The Big Bang Theory Season 4, Episode 18

After you've
been thoroughly AMAZED.
The Big Bang Theory Season 5, Episode 12

Samba, twist, rock and roll,
you’d be AMAZED.
Money Heist Season 1, Episode 12