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.

Geez, I never realized
you were so COMPETITIVE.
The Big Bang Theory Season 7, Episode 3

I was really COMPETITIVE
with my roommate.
The Big Bang Theory Season 11, Episode 16

A COMPETITIVE advantage.
Westworld Season 2, Episode 10

It's an extremely COMPETITIVE,
cutthroat sport.
The Big Bang Theory Season 3, Episode 6