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.

The national RESERVE,
on carts propelled by outboard motors!
Money Heist Season 3, Episode 8

Please RESERVE chitchat for your breaks,
Ms. Jensen.
The Big Bang Theory Season 6, Episode 3

A state can allow you to go into
the national RESERVE and steal the gold,
Money Heist Season 3, Episode 5

I'd like to go ahead
and RESERVE May 12.
The Big Bang Theory Season 11, Episode 17

They're melting the national RESERVE! Why?
Money Heist Season 3, Episode 7