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.

"reducing mighty
edifices to DUST,
The Big Bang Theory Season 5, Episode 15

And I've got a handful of pixie DUST
with your name on it.
The Big Bang Theory Season 1, Episode 6

Until finally they dropped down
and became one with the DUST...
The Big Bang Theory Season 3, Episode 14

It's right off the DUST jacket
of my mom's last book.
The Big Bang Theory Season 5, Episode 12

Dust yourself off, forget it. Move on.
The Big Bang Theory Season 2, Episode 22