write an invitation letter

Make a plan for the day and write an invitation letter to your classmates.

为这一天订个计划并且给你的同学写封邀请信。

However in some occasions such as inviting somebody else to participate my birthday party, I'll write an invitation letter, since it is more formal way to inform.

然而，在一些非常正式的场合，比如：邀请别人参加我的生日会，我也会写要邀请信。毕竟这是一种更为正式的方式。

Write a letter to a friend refusing an invitation to a party. Supply a suitable Introduction and Conclusion. Use the following ideas to write your Purpose.

朋友邀请你去参加一个聚会，写封信谢绝这一邀请。写出恰当的引言和结束语，“目的”部分按以下思路写。