在雅思General Writing 小作文中，选择合适的语气是一个非常重要的注意事项。
举例说，如果你写信给朋友或者家人，需要用Informal（非正式）的语气，而写信给公司或者老板，就需要用比较Formal正式的语气。
非正式信（Informal letter)示例：
Write a letter to your friend that you shifted to another flat
Describe the reason why you shifted
Describe the new flat and invite him to your new flat
Dear John,
I'm just writing to let you know that I've moved house.
As you know, I went for an interview for a job here in London. Well, they gave me the position!
It would have been impractical to travel down from Manchester every day, so we've found a house here, in a nice of London call Greenwich.
Our new house isn't ideal. If you ever fancy a trip to London, you're more than welcome to come and stay. It would be great to see you. From where we live, it's only a quick ride on the underground into the city centre, so we could do some sight-seeing together.
Keep in touch!
All the best,
Mike
本信Infomal tone总结如下：
Beginning: Dear John
Stating the purpose: I'm just writing to let you know that
Informal choice of language: As you know, Well, prices are crazy, on the bright side, it's got nice big windows, a lovely view, if you ever fancy, great to see you
Use of contractions: I'm, we've, isn't, it's
Ending: Keep in touch! All the best
正式信（Formal letter)示例：
You missed a flight due to a problem at the airport.
Write a letter to the airline. In your letter
Describe what happened that caused you miss the flight
Explain how missing your flight affected you
Make it clear what you would like the airline to you.
Dear Sir or Madam,
I am writing with regard to a flight that I missed due to a mistake by one of your employees.
Two weeks ago I was due to catch a flight to Roe, where I intended to spend four days on holidays. Unfortunately, the attendant at the check-in desk gave me a boarding card for a different flight, and I did not notice the mistake until I I arrived at the departure gate and it was too late.
As a result of the error, I was not allowed to board the flight to Rome, and this caused me great inconvenience. I had to book a new flight two later, which meant that I missed two days of holiday and I spent an extra 220 dollars.
As the mistake was caused by your company, I hope that you will compensate me for the cost of the additional flight, as well as for my taxi fares to and from the airport.
I look forward to receiving your response.
Yours faithfully,
Paul
本信Formal tones总结如下：
Beginning: Dear Sir or Madam
Stating the purpose: I am writing with regard to
Formal choice of language: due to, I intended, as a result of, caused me great inconvenience, compensate me, the additional flight
No contractions: I am (not "I'm")
Ending: I look forward to receiving your response. Yours faithfully,
总结:
Informal letter:
Beginning: Dear + first name
Friendly greeting: I hope this letter finds you well.
Contractions: I'm, didn't, couldn't, there's...
Questions: Do you remember...? Why don't you...?
Exclamation: ...earlier than I thought it was!
Linking: Well, Anyway, so, and
Phrases: had a great time, couldn't have asked for, working flat out, back to normal
Ending: Hope to see you soon + first name
Formal letter:
Beginning: Dear Sir or Madam
No greeting necessary
No contractions: I am, did not...
Normally avoid direct questions: "I would like" instead of "Can I have?"
No exclamation marks (!)
Linking: However, Consequently, and, also
Phrases and vocabulary: with regard to, appliance, it was installed, the following day, failed to (meaning "didn't"), procedure, he assured me, report the issue, contacted, under warranty, I am entitled to, replacement, phone me personally
Ending: I await your prompt response, Yours faithfully + full name
部分内容取材于Simon IELTs，在此衷心表示感谢：）