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.

in that PLAYGROUND who surrendered
before he was caught.
Money Heist Season 1, Episode 4

When you were a child,
what games did you play in the PLAYGROUND?
Money Heist Season 1, Episode 4

...just to single out the poor gibbon
as the weird kid on the PLAYGROUND.
The Big Bang Theory Season 8, Episode 8

An anonymous tip brought police
to a PLAYGROUND...
Breaking Bad Season 3, Episode 12

This is a university,
not a PLAYGROUND.
The Big Bang Theory Season 5, Episode 17