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.

Why don't you try
sticking them up your ass SIDEWAYS?
Breaking Bad Season 2, Episode 9

Sideways.
Game of Thrones Season 2, Episode 5

...and this SIDEWAYS asshole is in
my back seat humming "Danny Boy."
Breaking Bad Season 3, Episode 12