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.

Perhaps TOMORROW I could observe
the two of you together?
The Big Bang Theory Season 12, Episode 22

How 'bout TOMORROW?
The Big Bang Theory Season 11, Episode 10

Hey, Raj,
do you wanna go with me TOMORROW?
The Big Bang Theory Season 10, Episode 20

I love you too. Sweet dreams.
I'll talk to you TOMORROW.
The Big Bang Theory Season 6, Episode 1

Leonard, if you're not busy TOMORROW,
The Big Bang Theory Season 10, Episode 20