什么情况下用一般现在时表示一般将来时

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.
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.
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.
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.
中学英语中,有些从句只能用一般现在时形式表示一般将来时,现归纳如下,以供参考.
在由if,unless引导的条件状语从句中,如：1. If it doesn't rain tomorrow, there will be a sports meet in our school. 2.You will miss the train unless you set out at once.
在由when,before,after,as soon as,once,till/untill引导的时间状语从句中,如：1.When you meet a new word,you may look it up in your dictionary. 2.When you arrive in London at 8 tomorrow morning, it will be 4 o'clock in Bejing in the afternoon. 3.You will have to get everything ready for the party before I come this evening. 4. After you finish reading the whole book, you will be able to know its real meaning. 5.I'll write to you as soon as I get there. 6.Once you understand its meaning, you will easily remember the word. 7.I'll not leave here until/till he comes back.
在由as/so long as（只要……）引导的条件的状语从句中,如：
1.It is hard to avoid mistakes, as/so long as you correct them conscientiously, it will be all right.
2.so long as one inch of this deck remains above water, here is ho
参考资料：http://www.hongen.com/eng/pub/yufac/1107.htm