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 weapons are in
an UNMARKED grave
behind the church.
Westworld Season 2, Episode 4

They're in an UNMARKED grave
out back.
Westworld Season 2, Episode 4

They're printing their own UNMARKED money.
Money Heist Season 1, Episode 4