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.

The only tree BARK I know
that humans consume is cinnamon.
The Big Bang Theory Season 4, Episode 3

Don't BARK at me. I fell too.
The Big Bang Theory Season 3, Episode 14

I need fennel root for those with fever,
willow BARK. Mostly I need milk of the poppy.
Game of Thrones Season 2, Episode 7

Well, beavers eat tree BARK.
The Big Bang Theory Season 4, Episode 3

Bark once if you need me
to call PETA.
The Big Bang Theory Season 7, Episode 10