来自VOA的[ Ask a Teacher ] The Difference between Will and Would ? (2021/7/04) 节选
Will和would是我们经常用到的情态动词，但是很多人只会用will，而一部分人懂得用would去替代那些在过去式句子中的will，感觉用的很机械化，用途很狭窄。
我们来看一下正宗美式英语是怎么教你用will和would的吧，先看一下VOA的开场白：
Thank you for your question. It centers on modal auxiliaries – words that come before, and change the meaning of, the main verb in English sentences. When you study will and would, be sure that you have a strong understanding of the main verb.
解答：
VOA说得很清楚，will和would都是情态动词，而他们具体怎么用，代表什么意思，取决于句子的主动词。如果你能很清楚地了解了主动词的表达含义，那你就能用对will或would。
1、Grammar books often call will the base or present form and would the past form. However, modals do not always connect to exact ideas about present and past time.
Consider these two examples. The main verb is go.
I will go to the store tomorrow.
I would go to the store, but my car isn't working!
The first statement suggests a future action, while the second statement suggests a wish about a present situation.
解答：
语法书上都是写will代表基本的现在形态或者将来时，而would是过去式，但很多时候并不是那么精确匹配的。
举了用go主动词构成的两个句子：
（1）I will go to the store tomorrow.
（2）I would go to the store, but my car isn't working!
两个句子都是表示将来的动作，但实际上（2）表达的是本来想去的，但是因为别的事情成行不了，这种方式实际上就是表达一个愿望，表明这个事情并没有发生，这个后面会细讲。
2、Will can also be used for commands, as in: You will finish your homework!
解答：
Will这种特殊用法，我们可以在美剧里经常可以听到，尤其是刑事侦探，黑帮，军营等热血题材的电影里。可用于第二人称陈述句，表示说话人的建议、命令，有“应该、必须”之意。
例：
Lieutenant: You will start training right now!
Soldiers: Yes sir!
3、Would often suggests a wish or desire about a present situation.
For example: I wish it would stop snowing.
解答：
这是一个would的很常用的用法，一般跟主动词wish配合。不用管主动词的时态，would都是用来表达说话者的意愿。
例：
I wished my son would be a doctor at that time, but right now I wish he would be a scientist in the future.
以前我希望儿子能做个医生，但现在我想让他将来成为一个科学家。
4、Would can also be used for polite requests, as in: What would you like to eat?
Or: Excuse me, would you be able to tell me where the train station is?
解答：
Would和will都可以用在疑问句中用于第二人称，表示提出请求或询问，would会显得比较委婉，所以建议大家向别人提出请求时，使用would。
5、Think of will and would as family members, perhaps sisters.
Will, the strong, firm sister, is often used for commands or actions.
Would, the quieter, softer one, is used more for expressing dreams, wishes, possibilities and polite requests.
解答：
VOA这里做了一个形象的比喻，will和would是一对姐妹。will是意志坚强和态度强硬的姐姐，一般用来发号施令；would是安静的软妹妹，一般用来表达愿望，梦想，以及礼貌的要求。VOA这样的比喻，是对will和would的一个总结，大概规定了两者的使用场景。
当然，除了VOA的解释，我想做一个自己的总结：
Will
1、用于表达“意志”，“决心”，态度是坚定的
I will finish it on time, that is a promise!
我答应你，我会按时完成的！
I definitely will be a layer in the future!
我一定会成为一个律师的！
2、用于带有命令性质的建议，不能反驳的，无关句型是陈述句还是疑问句
You will do that！
你会做的！
Will you get away right now?
请你马上离开！
Would
1、用于表达虚拟语气的意愿，或者假设
If he were here, I would tell him the truth.
如果他在这里，我就会告诉他真相。
If I was you, I would do that.
如果是我，我会做的。
I wish I would be there to stop him.
我真想我当时能在那里，这样我就能阻止他了。
2、委婉地提出请求、询问、建议等，用于疑问句
Would you help me？
帮帮我好吗？
What would you like?
请问你想吃点什么呢？
