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 take my hat off before you.
-And your KNICKERS.
Money Heist Season 1, Episode 8

really dampens the KNICKERS:
Westworld Season 2, Episode 3

-But, you wear thongs, don’t you?
-I’m not going to wear KNICKERS.
Money Heist Season 1, Episode 13