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.

it's possible that
I'm not boyfriend MATERIAL.
The Big Bang Theory Season 5, Episode 12

your genetic MATERIAL
for his baby?
The Big Bang Theory Season 12, Episode 12

Not a good idea,
my hair is a coveted nesting MATERIAL.
The Big Bang Theory Season 10, Episode 21

...you've only selected seven hours
of reading MATERIAL.
The Big Bang Theory Season 4, Episode 9

We've only got MATERIAL
enough for six.
Breaking Bad Season 2, Episode 9