要解决这个问题，我们需要根据不同的语句类型在做判断。

1)下列动词：come, go, arrive, leave, start, begin, return的一般现在时表将来。这主要用来表示在时间上已确定或安排好的事情。

The train leaves at six tomorrow morning.

When does the bus star? It stars in ten minutes.

2)倒装句，表示动作正在进行，如：

Here comes the bus. = The bus is coming.

There goes the bell. = The bell is ringing.

3)在时间或条件句中。

When Bill comes (不是will come), ask him to wait for me.

I'll write to you as soon as I arrive there.

4)在动词hope, take care that, make sure that等后。

I hope they have a nice time next week.

Make sure that the windows are closed before you leave the room.