1. 说明原因：
This is
owing to …
due to …
a result of …
because of …
注：owing to 通常用于不好的消息。如果想在原因中使用动词，请加上the fact that的从句。

环境：
increase prices --- fall of the dollar
We have been force to increase our prices. This is owing to the fall of the dollar.
Delay the delivery of the goods --- strike by airline pilots
We have been forced to delay the delivery of the goods. This is owing to the strike by airline pilots.
Increase all salaries by 10% --- rise in sales
We are able to increase all salaries by 10%. This is the result of a big rise in sales.
Cut all salaries by 10% --- fall in sales
We have been forced to cut all salaries by 10%. This is due to the fact that there has been a fall in sales in the past ten months.
Cannot deliver your new order --- we have not received your payment fro the last order
We regret that we are unable to deliver your new order immediately. This is owing to the fact that we have not received your payment for the last order.
Cancel the meeting --- a lot of staff have been ill
We have been forced to cancel the meeting. This is because some members of our staff have been ill.

2. 请求采取行动：
Please could you …
We would be grateful if you could …
We would be appreciate it if you could … as soon as possible.
without delay.
immediately.
注：please could you … 是最直接的方式。在要求一些一般性的事情时，可以使用这种表达。

环境：

You have seen an advertisement in the newspaper for a post as office manger. You want an application form.
I would appreciate it if you could send me an application form.
The photocopier in your office has broken down. You want to have it repaired, quickly.
We would be grateful if you could send a repairman to fix our photocopier as soon as possible.
You have moved your office and you want the post office to forward your letters to your new address.
Please could you forward my letters to my new address.
You want the telephone company to put another telephone in your office. You need it urgently.
We would appreciate it if you could put another telephone in our office immediately.
You have written to a company and you want them to reply quickly.
I would be grateful if you could give us a reply quickly.

3. 抱歉：
We must apologize for …
We apologize for …
We are extremely sorry for …
注：以上句型后请使用动词ing形式。
以上句型中的for可以换成that，然后用从句表达。

一般来说，解释产生问题的原因，然后在信的结尾处再次表达歉意。
再次抱歉：
Please accept our apologies once again.
We hope that this has not caused you any inconvenience.
With apologies once again.

4. 要求提供信息：
Please could you
We would be grateful if you could
We would appreciate it if you could give us further details about
inform us （about/if） …
let us know （ about/if ） …
We would like to know （ about/if ） …
注：如果需要特别重要的信息，可以在以上句型前使用：in particular。

环境：
You wrote a letter to someone and they haven't replied. You want to know if they received the letter.
We would be grateful if you could let us know if the letter has reached you.
A businessman is going to your country. He wants you to get a visa for him. You need all the details about his passport （his nationality, date of birth, where his passport was issued, and when it expires）。
Please could you give details about your passport. I would like to know your nationality, date of birth, where your passport was issued and when it expires.
You want to know about the same businessman's flight （flight number, date and time of arrival）。
In particular, I would like to know your flight number, date and time of arrival.