投诉信通常包括以下几个方面的内容：说明投诉的原因并表示遗憾;实事求是地阐述问题发生的经过，切忌夸大其词;指出问题引起的后果;提出批评及处理意见，或敦促对方采取措施，或提出所希望的赔偿以及补救方式。
投诉信的写作策略：说明投诉问题——描述具体情况——期待解决方案。
注意事项：写投诉信时语气要冷静、郑重、克制，不必过于礼貌。但也要就事论事，不能进行人身攻击。同时，在描述问题时尽量采用被动句式，使描述更加客观合理。
投诉信开头常用句式和套话：
I am writing to complain about/that.。.
I am writing to make a complaint about.。.
I am writing to express my concern/dissatisfaction/disappointment about.。.
I feel bad/sorry to trouble you but I am afraid I have to make a complaint about.。.
I am most reluctant to complain， but.。.
I am writhing to advise you that I find.。.unsatisfactory.
I wish to draw your attention to the problem/fault.。.that I bought.。.
It is with great reluctance that I must inform you that.。.
投诉信结尾常用句式和套话：
I trust you will take my complains seriously and.。.
I will appreciate it very much if you could.。.
I would be perfectly satisfied if you can kindly.。.
I understand you will give immediate attention to this matter.
I would like to have this matter settled by the end of.。.
Frankly speaking， I am not prepared to put up with the situation any more.
I must have you fully understand that without a satisfying solution， I will reserve my right to take legal action.
I would be grateful if you could.。.
I would appreciate it if you could.。.
考研英语写作建议信是对收信人就某一问题提出建议和忠告。它有可能是写给某个组织或机构，就改进其服务质量提出建议或忠告;也可能是写给个人，就其人生中的某个重大决定提出自己的看法、建议和观点。考生需要注意：建议信和投诉信在某些情况下既有相同，又有不同，在改进质量的建议和忠告方面应该有很多的共通点，但如果是关于个人的重大决定就不应该用很生硬的语言了。
