ברכה ליום הולדת של מורה \ מרצה \ גננת באנגלית
Your discipline is paramount.
You have been great contributor to my character.
If you had not been there, I believe I would have been a very naughty person who is hard to control.
It is for this reason that am writing this message to wish you happy birthday.
It might not be possible to know your age but one thing I know is that you are the best among your age mates.
Continue with the same spirit of correcting young people no matter the method you use even as you turn into a new year of your life.