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.

RESPOND effectively, and beat them.
Game of Thrones Season 7, Episode 6

How do you RESPOND to
these charges against your brother?
Game of Thrones Season 5, Episode 6

(STAMMERS) Well, I texted you,
but you didn't RESPOND,
The Big Bang Theory Season 10, Episode 18

I mean, should I RESPOND to their email?
Ignore it?
The Big Bang Theory Season 9, Episode 24

I assume you'd like to RESPOND
to one of the suggestions
The Big Bang Theory Season 5, Episode 16