1、投诉信

　　投诉信的开头常用句式和套话

　　I am writing to inform you that I am dissatisfied with your …

　　投诉信的结尾常用句式和套话

　　I understand you will give immediate attention to this matter.

　　I would like to have this matter settled by the end of …

　　2、询问信

　　询问信的开头常用句式和套话

　　I would be most grateful if you could send me information regarding/concerning …

　　I am writing to see if it is possible for you to provide me with information regarding …

　　询问信的结尾常用句式和套话

　　Your prompt attention to this letter would be highly appreciated.

　　I am looking forward to hearing from you.

　　3、请求信

　　请求信的开头常用句式和套话

　　I am writing to seek for your assistance in …

　　请求信的结尾常用句式和套话

　　I would like to thank you for your generous help in this matter.

　　4、道歉信

　　道歉信的开头常用句式和套话

　　I am writing to apologize for …

　　I am writing to say sorry for …

　　道歉信的结尾常用句式和套话

　　I sincerely hope that you will be able to think in my position and accept my apologies.

　　5、感谢信

　　感谢信的开头常用句式和套话

　　I would like to convey in this letter my heartfelt thanks to you for …

　　感谢信的结尾常用句式和套话

　　I must thank you again for your generous help.