一般就某个社会问题或个人问题给出自己的意见或建议，比如环境要改善的谏言;研究生活应该如何进行，等等。分两类建议信，一类写给机构，语言要正式严谨;而如果写给熟人，则语言可以随意一些。
第一段概括写出写信的大致内容：I am writing here to provide some advice to improve......\You have asked me for my advice concerning/with regard to......
第二段详述具体的建议，可分条阐述：To begin with,......Besides,......Moreover,......
第三段总结段：I hope you will find these suggestions useful and I would be ready to discuss this matter with you to further details. I am looking forward to your reply and wish you a good work.