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.

My leg is killing me. Thanks for asking.
The Big Bang Theory Season 2, Episode 11

Thanks.
Yeah.
The Big Bang Theory Season 12, Episode 21

Thanks, so do you.
The Big Bang Theory Season 6, Episode 5

Thanks for letting me practice
my sales pitch on you. I really appreciate it.
The Big Bang Theory Season 8, Episode 4

Uh, Hufflepuff from Harry Potter. 73
00:04:19,093 --> 00:04:20,261
Thanks.
The Big Bang Theory Season 9, Episode 20