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.

Oh, I went to the LIBRARY
The Big Bang Theory Season 7, Episode 22

I saw that in the LIBRARY.
Westworld Season 2, Episode 10

Fort Knox doesn't have
a secret physics lending LIBRARY.
The Big Bang Theory Season 8, Episode 20

A bully chased me through
the school LIBRARY
The Big Bang Theory Season 7, Episode 20

I stole a considerable number
of books from the Citadel LIBRARY,
Game of Thrones Season 8, Episode 2