be going to 不是固定短語，而是英語的固定搭配，或稱是英語語法規定的。它表示多重作用。

（1）表示打算

He is going to be a dentist when he grows up.

他長大了想當牙醫。

Is he going to lecture in English or in Chinese?

他打算用英文講課還是用中文？

She is not going there tonight.

她今晚不打算去那裡。

（2）表示決心

The army is going to remain in this town.

軍隊決定繼續待在這座城裡。

We are going to have all the locks in the house changed.

我們要把屋子裡的鎖全換掉。

（3）表示即將

There"s going to be a thunderstorm.

雷雨即將來臨。

My cousin is going to have a baby.

我表姐要生孩子了。

（4）表示肯定

But it"s going to be a very tiring five years for me.

但是對我來說，這肯定是非常累人的五年。

I think it"s going to be fun.

我認為那一定很好玩。

（5）表示可能

It"s going to be warm tomorrow.

明天天氣會很暖和。

I"m going to be sick.

我要病倒了。

（6）表示建議、命令等

You are going to put up a notice on the wall of your classroom about not smoking.

你們應該在你們教室的牆上貼一個不許吸菸的告示。