be going to的用法

打算,计划做某事……
be going to
1.计划(或打算、决定)(做某事)
2.即将(发生某事)
3.可能会(发生某事)
4.正打算,就要,将要
5.打算要,想要；就要：
She is going to write to him.
她就要给他写信了.
It is going to snow.
天就要下雪了.