One of my adult ESL students once gave me a sympathy card (given when someone has died) on Mother's Day because it had such a lovely picture on the front. (She didn't know enough English to understand what was written inside the card.) I still have the card because I know she gave it to me with love and respect.

You write very well. Write what's in your heart and your professor will understand. If you do make a few mistakes, it doesn't matter. The professor will love receiving a card from you.

You might want to write something along the lines of:

"Dear (professor's name):

Thank you very much for _______ (fill in what you like)! I really appreciate everything you've done for me and our class- I'm very sorry that you are not feeling well and I hope that you feel better very soon! We miss you.

God bless you, and again I hope you feel better soon.

Sincerely/Love/From/Regards, (select one!)

_____ (your name)

I'm sure he will appreciate your gesture of kindness- good luck!

Just write what you wrote here: Just heard that you are unwell. Thank you for being such kind person. Bless you and wishing you a return to good health soon.

You demonstrated that you write rather well, just say what you feel. Usually, we have "get well cards" that you can get from any store, and you can add anything you wish

a touch under the impression of alcohol guy is strolling alongside the line, marvelous a splash, whilst a police vehicle pulls up next to the dimensions down. "hey, chum!" yells the police officer, "the place are you going?" "To a lecture". the guy replies "A lecture? Who'd be giving a lecture at 2-thirty interior the morning?" asked the officer, puzzled. "my spouse" replied the guy

Write what you feel! he will love it for the gesture. :)