... gratitude? - Make a phone call - Write an email - Send a letter, … In this period, we will study and practice writing a formal thank-you letter 1 donate /dou'neit/ (v): tỈng, cho (tiỊn) lµm tõ thi n ... faithfully - I am most grateful to you for … - I would like to express my sincere thanks to you for … - On behalf of … I am writing to thank you for … - My heartfelt thanks go to you for … - I am ... comment on the language of this letter It is the language of a formal letter: + Formal greeting: Dear Sir/Madam + Complete sentences, full forms: I am very happy to …/I think that …/We will … +...