I’m delighted to hear from you. You asked me something with regard to…………., and therefore, now I’d like to present some detailed information as follows.
I hope what is mentioned above might be helpful for you. Best wishes!
I am writing with disappointment/dissatisfaction to complain about the annoying quality product ... I really hate to complain, but ... really disappoints me.
(解释原因)：The reason why I complain it is that I bought a ... but unfortunately, there’s something wrong with it now. More specifically(更具体地说), it ...
(二次强调)： What’s most unacceptable is that ...This is the worst experience I have ever had.
(表达诉求)： Nevertheless, I believe you will take my complaints seriously and adopt effective measures to handle the problem.
(期待回复)：I would appreciate it very much if you can reply at your earliest convenience.
I am writing (these few lines) to convey my heartfelt gratitude/appreciation (from the bottom of my heart) to you.（写信目的）
(解释原因)：……….. for the reason that you ... , I fortunately, ... (好的结果)
(反面假设)： If it had not been for your enthusiastic assistance I fear that the consequences might have been much more serious.
(二次致谢)： Therefore，oceans of thanks for your enormous support and assistance! (*Words fail to convey my gratitude to you.)
a) Excessively disappointed and annoyed, I’m writing this letter to express my dissatisfaction with the computer bought from your store on October, 16th, 2016.
b) I am writing to inform you that I am dissatisfied with the bad service of the school canteen.
c) On September 10, the delivery of the computer was received, but I regret to say that the screen of the computer was damaged because of improper packing.
失望与生气：Excessively disappointed and annoyed, I’m writing to …
表达不满：express my dissatisfaction with sth
complain to sb about sth
make a complaint about sth to sb
be dissatisfied with sth
a) Many thanks for your kind hospitality and the honor you showed me during my recent visit to your university. It was nice of you to introduce to me so many famous professors and distinguished scholars at your university.
b) Without your kindness and sincerity, my stay back then would have been quite different.
c) Never had I known a language could be taught and learned that way, which, up to this day, remains a guide to my English learning.► 点评：热情好客：hospitality 真挚：sincerity
其他表达感谢：Words fail to express my thanks for ...Words couldn’t express how grateful I am to you for what sb have / has done sthI would appreciate it if you could do sth. 09
I am profusely sorry to you that I won’t be able to………...
(解释原因)：……..for the reason that ... And unfortunately, ...(坏的结果)
(反面假设)：If it had not been for my carelessness, the situation would be better.
(二次致歉)：Under such circumstances, I feel apologetic for the inconvenience caused already.
Hopefully you can understand my situation and accept my apologies.
a) Excessively sorry / With regret, I’m writing this letter to give you my sincere apology for my failing to accompany you to travel to Beijing at the appointed time.
b) I’m writing to apologize for having forgotten to return the “the Beatles” CD to you when I left China. I was in such a hurry that I packed everything in my luggage without checking carefully.
对不起，很抱歉：Excessively sorry / With regret, I’m writing to …
向某人道歉：give sb my sincere apology
make an apology to sb
apologize to sb for sth
owe sb an apology
Words fail to express my apology for ...
Words can’t express how regretful I’m because ...
a) Thank you for your letter to invite me to your birthday party. However, much to my regret, I’m unable to accept your kind invitation due to the fact that I’m busy preparing for a singing competition which is of great significance for me.
b) It gives me great pleasure to be invited to attend your graduation ceremony on June 30th in the hall in our university. I would like to accept your warm invitation but I can’t due to an earlier appointment.
遗憾的是：much to one’s regret
不能做到某事：be unable to do; fail to do sth; can’t make it to do sth
因为：due to the fact that ...
重要：which is of great significance / importance; which is essential / vital / crucial
委婉拒绝：sb would like to do sth but ...
I’m writing to apply for the position of ... as you have advertised in the newspaper .../recommend myself as a qualified candidate for / I am writing in the hope that I may obtain the opportunity to ...
(素质经历)： Actually，I have similar experience of ..., and the experience will greatly contribute to my work.
Additionally, I feel qualified/competent for the job for the reason that I ...
(表达期望)： I am available for a personal interview if you are interested in my application. And I shall be very grateful if offered this precious opportunity.
On hearing the notice that teachers and students from Phoenix Central High School are coming to visit our school, I am very glad to extend a warm welcome and apply to be a host family.
听说 / 了解……：On hearing / learning ...
表示热烈的欢迎：extend a warm welcome 切记：尽量不用express a warm welcome，这个不地道
申请：apply to be / make an application to be
Knowing you are fascinated by _________ （非谓语解释说明背景）, I am extremely delighted to invite you to _________ （邀请事宜）. Here are some details concerning it.
As scheduled, the_______ (活动) will be in_______ (地点) on ________(举办日期), which will last for __________(定语从句进一步解释说明持续时间). During the exhibition, a wide range of activities will be held, enabling you to have a better understanding of Chinese traditional culture. To begin with, it will provide you with a platform to ________(具体活动1). Additionally, what you will also enjoy is ________ （具体活动2）. I’m confident that you will have a wonderful time.
I sincerely hope that you can attend the_______ (活动) . Please confirm your presence at your earliest convenience. Your early reply will be highly appreciated.
a) With great pleasure I am writing to invite you to be the judge for our English speech contestheld by the English Club and sponsored by the Foreign Language School on Friday evening in the student center. (guide导游，tutor导师 / 助教，coach教练，consultant / advisor顾问)
b) On behalf of the Students’ Union of English Department, I feel honored to extend an invitation to you togive us a speech on Chinese history.
邀请某人做某事：invite sb to do sth; extend an invitation to sb to do sth
代表：on behalf of ...
参加：take an active part in; participate in; be involved in; engage in
发表演讲：give / deliver / address a speech
I am writing to put forward my suggestions/proposals in response to your previous letter asking for advice.
(重提问题)： You have raised a question/doubt in your letter that ...
(给出建议)： Accordingly, here are a few suggestions for your reference as follows.
First and foremost, if I were you, I would do...
In addition，measures are supposed to be taken to ...
Last but not least, as far as I am concerned, it is quite necessary for you to ...
(希望采纳)： On the whole, it is just for your reference and I will appreciate it very much if you can take it into account and in the meanwhile hopefully it can be of use to you. But Your kind consideration of my suggestions will be highly appreciated.