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.

And we will be with you
UNTIL time comes to an end.
Game of Thrones Season 2, Episode 10

a fact that wasn't discovered
UNTIL they competed
The Big Bang Theory Season 5, Episode 14

...on the barbecue and eat it
UNTIL we're all obese.
The Big Bang Theory Season 6, Episode 6

he was a squire
UNTIL a few months ago.
Game of Thrones Season 1, Episode 5

Not UNTIL I met the king
of the grim, bearded, stinking barbarians.
Game of Thrones Season 3, Episode 2