assuming you are chosen to represent your class in a prize giving ceremony , write a semi formal letter to your principal appreciating him for choosing you to r

pour commencer tu peux dire:

Dear principal,
I would like to sincerely thank you for choosing me to represent the class.
That is a real honour for me and i promise to do it well and make sure to not disappoint you.
I have an endlessly admiration and enthusiasm towards you and I’m really grateful for everything you do for us as the principal of our dear, precious school.
Again, I promise to respond to your expectations and do well.
I am truly honoured and thankful.
Thank you.