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.

Is there any reason
you're keeping this dead GOLDFISH?
The Big Bang Theory Season 6, Episode 19

Oh, I don't know. Remember what happened
when I took care of your GOLDFISH?
The Big Bang Theory Season 6, Episode 24