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.

Correction.
Missy can date whoever she wants.
The Big Bang Theory Season 1, Episode 15

- I'm gonna go home and wash my hair.
- Don't you dare, MISSY.
The Big Bang Theory Season 2, Episode 16

By the way,
may I speak to Missy, please?
The Big Bang Theory Season 1, Episode 15

Penny, this is Sheldon's twin sister.
Missy, this is our neighbor Penny.
The Big Bang Theory Season 1, Episode 15

- Sheldon, are you gonna introduce us?
- Oh, all right. This is Missy.
The Big Bang Theory Season 1, Episode 15