Why weren't you at work yesterday?
What reason do you have for missing school?
I wasn't really feeling well.
I was sick.
What was wrong with you?
What was your problem?
have a cold, headache, stomachache
Are you feeling any better?
Do you want anything to make you feel better?
还不舒服就说I'm still feeling under the weather.
没问题了就说I'm OK now.
I hope you feel better.
I'd appreciate that!
Thanks a lot!