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.

If you don't get up
and FETCH me some herrings,
Vikings Season 1, Episode 6

Mmm. Lord Tyrell, be a good man.
Fetch my quill and paper.
Game of Thrones Season 4, Episode 6

Girl, FETCH me the History of the
Greater and the Lesser Houses.
Game of Thrones Season 2, Episode 6

Fetch that water.
Game of Thrones Season 2, Episode 5

Now get up and FETCH me
some pickled herrings.
Vikings Season 1, Episode 6