英文邀请信通常包含以下几个部分：
标题 ：通常在信的最上方，表明信件的目的是邀请。称呼：
根据受邀者的身份和关系，使用适当的称呼，如“Dear Mr. Smith”或“Dear Professor Wang”。
邀请内容
活动性质：
说明邀请参加的活动类型，如“birthday party”，“luncheon”，“conference”，“exhibition”等。
活动时间和地点：明确指出活动的日期、时间和地点，如“May the fifth, at twelve o’clock”，“April 15th to 20th”等。
活动目的：简要说明举办活动的目的或期望，如“to give us a speech on Chinese History”，“to celebrate my birthday”等。
特别说明：如果有任何特殊要求或期望，如“Please tell me what kind of audio-visual equipment you’ll need”。
结束语：
表达期待受邀者回复的意愿，如“We are looking forward to favorable answer”，“Please say you’ll come!”等。
落款：
包括发件人的姓名、职位和联系方式，如“Sincerely yours, Jimmy”，“Affectionately yours, Li Ming”等。
示例1：
```
Dear Professor Wang,
On behalf of the Student Union of the English Department, I am writing to invite you to give us a speech on Chinese History. We are going to have such a speech at 2:30 pm. Please inform us whether you could come. We are looking forward to a favorable answer.
Sincerely yours,
Jimmy
```
示例2：
```
Dear Zhang Ying,
Will you come to luncheon on Friday, May the fifth, at twelve o’clock？ My niece Mary is visiting us and I think you will enjoy meeting her. She is a charming, very pretty girl… and very good company! John and Jane will be here, and perhaps we can give a dance after luncheon. Do say you’ll come!
Affectionately yours,
Li Ming
```
示例3：
```
Dear Mr. and Mrs. Smith,
It has been a while since we last met, and we have been following your research with great interest. From our initial communications, we attest that you meet our English language requirements for the research work. You will be conducting research of…
```
请根据具体情况调整邀请信的内容和格式。