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.

...he got such a bad SUNBURN,
we had to cut him out of it.
The Big Bang Theory Season 8, Episode 9

If Raj dies, it'll be from frostbite,
gangrene, acute SUNBURN...
The Big Bang Theory Season 2, Episode 23