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.

But trust me, in a HIGHLY controlled
environment such as this...
Breaking Bad Season 3, Episode 10

...HIGHLY active, HIGHLY profitable
marketplace.
Breaking Bad Season 5, Episode 8

It's not terrific.
Lots of HIGHLY unlikely things happen.
The Big Bang Theory Season 9, Episode 15

...HIGHLY active, HIGHLY profitable
marketplace.
Breaking Bad Season 5, Episode 8

Well, this is HIGHLY insulting.
The Big Bang Theory Season 10, Episode 12