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.

Look, if I don't pass chemistry,
I have to go to SUMMER school.
Breaking Bad Season 2, Episode 7

Summer has ended, hard days lie ahead.
Game of Thrones Season 3, Episode 3

I took a scuba-diving course
over the SUMMER...
The Big Bang Theory Season 4, Episode 4

but if you're trapped in Summer for too long,
you'll forget what it was to be human.
Game of Thrones Season 4, Episode 2

Summer snows, my lady.
Game of Thrones Season 1, Episode 8