英语等级考试三级考试常考的信件有:邀请信, 应征信,求职信, 感谢信, 致歉信, 道贺信, 投诉信, 询问信, 推荐信。
（一）英文书信的组成
英文书信通常有包括以下几部分:
1．信头(Heading): 指写信人的地址和写信日期
信头的目的是使收信人知道书信来自何处，何时发出。信头一般位于信函的右上角，包括发信人的地址和写信日期。
信头的地址的写法要注意英文和中文的不同，英文应遵循“先小后大”的原则，第一行写门牌号和街道的名称，第二行写区、市名、省名、国家名。国家名之前加上邮政编码。门牌名与街道名之间不用逗号隔开。最后一行写上发信日期。日期一般有以下几种写法：
12th Sept, 2006 12 Sept, 2006 Sept. 12th, 2006
如，
Mr. Zhang Peng
Department of Foreign Language
Jiangxi Teachers’ College
Nanchang, Jiangxi Prov., 330241
P.R.C.
Sept. 12, 2006
2．信内地址(Inside Name & Address): 指收信人的姓名和地址
信内地址一般位于信函的左上角，位于信纸的左边顶格，低于信头一两行写起。
3．称呼 (Salutation): 对收信人的称呼用语
称呼是写信人对收信人表示尊敬的敬称。称呼从信纸的左端顶格写起，比信内姓名和地址低一行，。称呼有多种，视写信人和收信人的关系而定。每个开头字母用大写，结尾用逗号不用冒号。
对男士的称呼，多用Mr., 对女士的称呼,多用Mrs., Madam, Miss或Ms.,但是需要注意的是,这些称呼用在姓氏前或姓氏和名字前,但是不能使用在名字的前面。
4．正文(Body):
5．结束语(Complementary Close): 写信人对收信人的谦称
结束语从信纸的中间或稍右的地方写起，位于正文下面空两三行处。不同关系使用不同的结束语。
对于不熟悉的人或团体：Yours truly, Truly yours, Yours faithfully, Faithfully yours
对于上级和长者：Yours respectfully, Respectfully yours, Yours gratefully, Gratefully yours
对于朋友和亲属：Yours, Your loving daughter, Your devoted friend
6．签名(Signature):
7．附件(Enclosure):
（二）信件开头结尾常用语:
1. 信件开头常用语
I am writing to you to ask about the meeting to be held next month.
I have received your letter on Feb. 2nd 1998.
Thank you very much for the position you are offering.
It’s a long time that we haven’t seen each other.
I’m writing to introduce to you one of my good friends, Mr. Smith.
2. 信件文中常用语
Your presence on this occasion would be our greatest honour.
3. 信件结尾常用语
With many thanks.
Wish you the best of health and success.
Your early reply will be highly appreciated.
Expecting to hear from as soon as possible.
Looking forward to the pleasure of meeting you.
Regretting the inconvenience caused to you.
Thanks once more.
Many thanks for your kindness.
Thanks a lot and best wishes for you.
We sincerely hope that you’ll accept our apology and keep in contact with us.
We look forward to receiving your confirmation by letter or e-mail.