Question

Как написать письмо автору учебника на английском

Answer 1

Может похвалить за его учебник?
Hello! A am student in (номер класса) class. I need praise you fou your studentbook. Thank you very match for work! Your studentbook is perfect and training English very well!
Как-то так...

Answer 2

Thank You very much for your studenbook. It is really pleasure to study English with your book. It helps me much to learn English as possible as I can . Our teacher praise your student book . And there are in our class was too many pupils with bad marks . But now the situation become better than was. 
Kind Regargs for your work.