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 it because she's uneducated,
trapped in a MENIAL service position?
The Big Bang Theory Season 3, Episode 11

Of course. Even talking to you
is sufficiently MENIAL.
The Big Bang Theory Season 3, Episode 14

from the subpar education
and MENIAL life of an engineer.
The Big Bang Theory Season 9, Episode 18

No. I'm going to find
a similarly MENIAL job...
The Big Bang Theory Season 3, Episode 14

...but whose real talents lie
in MENIAL labor.
The Big Bang Theory Season 6, Episode 3