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.

...whose ability to comprehend
the American IDIOM...
The Big Bang Theory Season 4, Episode 4

Is that the American IDIOM
for "giant, big-ass desk"?
The Big Bang Theory Season 4, Episode 4