用 when 说将来的事，when 后面用一般现在时，主句用 will：When I get home, I'll call you.
When + 一般现在时，然后用 will
When I get home, I'll call you.
We'll have dinner when the movie ends.
试一试: Man: Can we talk? Woman: Yes, when I ___ this email. Give me a minute. 选出那位女士会说的话。 (will finish / start / finish / will start) 答案: finish — 她现在正忙着写邮件，所以等她写完再谈：when she finishes it；when 后面用一般现在时，不用 will。
as soon as、before、after：说时间先后
As soon as 的意思是某件事一发生就马上。as soon as、before 和 after 后面也用一般现在时。
I'll text you as soon as the bus comes.
Let's eat before the movie starts.
We'll talkafter the class ends.
试一试: Woman: Let's go hiking tomorrow. Man: Okay, but let's check the forecast ___ we go. 选出那个男人会说的话。 (after / before / as soon as) 答案: before — 要先查天气，所以是 before we go。
when 后面不用 will
when、as soon as、before 和 after 后面不用 will，用一般现在时。
We'll leave when the taxi comes.
He'll buy a car after he gets a job.
Not "We'll leave when the taxi will come." — say "We'll leave when the taxi comes.". when 后面用一般现在时，不用 will。
试一试: Man: Is dinner ready? Woman: Almost. We'll eat as soon as the rice ___ ready. 选出那位女士会说的话。 (won't be / is / will be / isn't) 答案: is — 米饭一好他们就吃，所以是 as soon as it is ready；as soon as 后面用一般现在时，不用 will be。