1、I am writing to invite you to…

我写信是为了邀请您……

2、I think it would be a great idea if you could participate in…

如果您参加……那就太好了。

3、I wonder if you can come…

我想知道您是否能来……

4、How would you like to join us in…

您想不想来参加我们的……？

5、Would you please drop me a line to let me know if you can come to…

您可以写信告诉我您能否来……吗？

6、My family and I would feel much honored if you could come.

如果您能来，我们全家将不胜荣幸。

7、I really hope you can make it.