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.

Until I meet Missandei
from the Isle of Naath.
Game of Thrones Season 7, Episode 2

The Sapphire Isle.
Game of Thrones Season 5, Episode 4

The flag of the Isle of Man is nothing but
The Big Bang Theory Season 9, Episode 15

It's called the Sapphire Isle
because of the blue of its water.
Game of Thrones Season 3, Episode 4

They call it
the Sapphire Isle. Do you know why?
Game of Thrones Season 3, Episode 3