Your Name
Your Address
Your City, State Zip Code

Date

Teacher Name
Grade or Title
School Name
School Address
School City, State Zip Code 

Dear Teacher Name:

The purpose of this letter is to express our gratitude for the extra time and attention you've given our Son/Daughter, Name this year.

Name's, grades have improved tremendously over the past few months. We have seen a significant change in his attitude and how he approaches his school assignments. With your coaching, he has realized that there is benefit to completing his homework on time and that there is value in pursuing knowledge. 

We are very impressed at your willingness to take such an interest in our son and persistently work with him to overcome his challenges.  We thank you again for your time and patience with Name.  School Name is lucky to have you as part of their staff.

Sincerely,
Your Name

cc: School Principal's Name