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.

...against a brawny member
of the WEASEL family.
The Big Bang Theory Season 4, Episode 2

I was only being polite.
Pemberton is a grade A WEASEL.
The Big Bang Theory Season 12, Episode 21

Why do you say he's a WEASEL?
The Big Bang Theory Season 12, Episode 21

(\"POP GOES THE WEASEL\"
PLAYING ON BOX)
"
title="
(\"POP GOES THE WEASEL\"
PLAYING ON BOX)
"
style="width: 100%;padding-left: 0px; padding-top: 0px;border: 0;"
width="100%" loading="lazy">
("POP GOES THE WEASEL"
PLAYING ON BOX)
The Big Bang Theory Season 6, Episode 21

Even if she fornicates
like a demonic WEASEL.
The Big Bang Theory Season 7, Episode 18