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.

I wonder if only a baby who is worthy
can SUCKLE at the bosom of Thor. Heh.
The Big Bang Theory Season 8, Episode 18

They didn't SUCKLE at your breast.
They are dragons, Khaleesi.
Game of Thrones Season 2, Episode 8