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.

Well, Colonel Williams said
another team at Caltech
The Big Bang Theory Season 11, Episode 8

Can't imagine the Colonel
is gonna be very happy
Westworld Season 2, Episode 2

Colonel.
Money Heist Season 3, Episode 7

Colonel Tamayo,
the usual procedure is to do a sweep.
Money Heist Season 3, Episode 4

There's a van. They've been here, Colonel.
Money Heist Season 3, Episode 7