什么时候用现在完成时和一般现在时表将来

一般现在时表将来
1）下列动词come,go,arrive,leave,start,begin,return的一般现在时可以表示将来,主要用来表示在时间上已确定或安排好的事情.例如：
　　　The train leaves at six tomorrow morning.火车明天上午六点开.
　　　When does the bus star?It starts in ten minutes.汽车什么时候开?十分钟后.
2）以here,there等开始的倒装句,表示动作正在进行.例如：
Here comes the bus.= The bus is coming.车来了.
There goes the bell.= The bell is ringing.铃响了.
3）在时间或条件句中.例如：
When Bill comes （不是will come）,ask him to wait for me.比尔来后,让他等我.
I'll write to you as soon as I arrive there.我到了那里,就写信给你.
4）在动词hope,take care that,make sure that等的宾语从句中.例如：
I hope they have a nice time next week.我希望他们下星期玩得开心.
Make sure that the windows are closed before you leave the room.离开房间前,务必把窗户关了.
现在完成时表将来
在时间或者条件状语从句中,现在完成时可以代替将来完成时,
如; I won't believe you until I have seen you in the jar with my own eyes.