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.

to INJECT it into his heart.
The Big Bang Theory Season 5, Episode 7

We're going to INJECT gas
at an extraordinary pressure.
Money Heist Season 3, Episode 6

And dazed too.
They had to INJECT me a sedative
Money Heist Season 1, Episode 13

to INJECT a tiny pellet
into the man's leg.
Breaking Bad Season 2, Episode 1

He used to INJECT himself
with some medicine each day.
Money Heist Season 1, Episode 8