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.

Stannis Baratheon laid SIEGE
to King's Landing.
Game of Thrones Season 3, Episode 5

We should set
the SIEGE lines 1,000 yards from Harrenhal.
Game of Thrones Season 3, Episode 1

There won't be a SIEGE.
The Mountain can't defend a ruin.
Game of Thrones Season 3, Episode 1

We are more prepared for a SIEGE
than they could ever be.
Game of Thrones Season 5, Episode 8

As I said, the SIEGE is under my command.
Game of Thrones Season 6, Episode 7