书信是日常生活中常用的文体，是用以交涉事宜、传达信息、交流思想、联络感情、增进了解的重要工具。书信一般可分为商务信件或公函（business letter or official correspondence）和私人信件（private letter）两大类。值得注意的是，英语书信的写法与汉语书信有一些明显区别，应特别加以区分。
①对没有头衔的男性一般称呼mr.。mr.用在姓氏之前或姓氏和名字之前，不可只用在名字之前，例如对的称呼，应该是：mr.或mr. white，不可是：mr. phil.若称呼多个男性，则在姓名前用mr.的复数形式messrs.。对一般以人名为名称的公司和企业常用这种称呼，例如：messrs. black and brothers布莱克兄弟公司。
④对外公函中对收信人的称呼，可用gentlemen（而不是gentleman），dear sir （s）和my dear sir（s）等。gentlemen之前不能加dear，后面也不能带姓名。用sirs时，前面常用dear一词，但也可单独用sir.若收信人是妇女，则无论已婚或未婚，都可单独使用madam或其复数mesdames.
yours， ever yours， yours as ever， as ever， yours affectionately， lovingly yours， （much） love， with love，lovingly， your loving son， your most affectionate， your devoted friend， devotedly，等等，意即：“您的”、“永远是您的”、“您的亲爱的”、“您的爱子（孩子、姐妹、侄、侄女、祖母）”、“您的挚友”等。
写给挚友的信有时也可用：
yours hurriedly， yours hastily， yours in haste，等等。
写信给挚友，表示歉意时，可用：
contritely yours， regretfully yours， yours in （with） regret， yours in （with） deep remorse等。
3）a thousand thanks for your kind letter of june 5，1997.
4）your kind letter of november 22th arrived this morning.
5）your letter which arrived this morning gave me great comfort.
6）in reply to your letter dated 4th july，i want to say…
7）thank you very much for your letter of august 2 and the gift you sent me on christmas eve.
8）what a treat to receive your kind letter of may 5th！
9）it is always a thrill to see your nice handwriting.
10）first of all i must thank you for your kind assistance and high attention to me .
11）with great delight i learn from your letter of this sunday that…
14）i am very much pleased to inform you that my visit to your country has been approved.
15）i wish to apply for teaching position you are offering.
16）i am too excited and delighted at your good news.
17）i am very obliged to you for your warm congratulations.…
常用的结束语有：
1）awaiting your good news，
2）looking forward to your early reply，
3）hoping to hear from you soon，
4）we await your good news.
5）i hope to hear from you very soon.
6）we look forward to your reply at your earliest convenience.
7）i look forward to our next meeting there in los angeles.
8）your early reply will be highly appreciated.
9）any other particulars wanted we shal be pleased to send you.
10）the help you give me is sincerely valued.
11）i hope everything will be well with you .
12）please let us know if you want more information.
13）i hope you always enjoy yourself.
14）i wish you very success in the coming year.
15）please remember me to your family.
16）with best regards to your family.
17）all the best.
18）with love and good wishes.
四、分类举例
1）私人介绍信（private letter of introduction）
例1
directions： one of your classmates and friends li fang will go to a university in new york to study for several months. please write a letter to an american friend in new york and introduce li fang to him/ her.you should write about 100 words and do not need to write the address.
dear mrs mark，
i am giving miss fang li， a classmate of mine， this note of introduction to you and mr. mark， when she goes to visit new york city. miss li is my good friend. she is invited by a university to study there for a few months. she is a kind young lady. i believe you will enjoy meeting and knowing each other and become friends. it is my hope that you will kindly invite her to stay in your house for a few days.
kind regards
very affectionately，
×××
*it is my hope that ……是一个强调句式，意同i hope that.
stay in your house表示在你家小住。
例2
directions ： your friend mary brown will go to washington d. c. next month. write a letter to tony who is there and introduce mary to him. you should write about 100 words and do not need to write the address.
dear tony，
this letter will introduce my best friend mary brown of whom you‘ve often heard me mention. she is going to be in washington d. c. next month to lecture. i want very much to have her meet you there.
and this seems like an excellent chance for you to meet each other. i think both of you will have a lot in common. so far as i know， you both are interested in modern literature. once you meet her， you will really enjoy her company. any kindness to her will be duly appreciated by me.
yours affectionately，
×××
*这是一个向朋友介绍朋友的介绍信。tony和mary都是写信人的朋友，在他看来，他们志同道合，有共同爱好，所以希望他们相识，信中说“you both are interested in modern literature once you meet her， you will really enjoy her company”。
