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.

Then all of a SUDDEN, boom,
it's popping up everywhere.
Breaking Bad Season 3, Episode 9

and all of a SUDDEN it becomes a
DEA case, what good does that do me?
Breaking Bad Season 4, Episode 3

I do not need
SUDDEN fits of homicidal rage.
The Big Bang Theory Season 9, Episode 12

The problem is that in my case I came
to a SUDDEN stop because of a gunshot.
Money Heist Season 1, Episode 10

and SUDDEN.
Game of Thrones Season 1, Episode 3