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.

A complication
does not release you from a VOW.
Game of Thrones Season 4, Episode 1

No, but I swore a sacred
VOW to protect her.
Game of Thrones Season 4, Episode 10

maybe you're released from your VOW.
Game of Thrones Season 5, Episode 2

I swore a VOW.
Game of Thrones Season 2, Episode 5

I was pledged to
marry one of you and I broke that VOW.
Game of Thrones Season 3, Episode 9