must 用于表示推测，它的肯定程度比 may, might, could, 大得多，一般只用于肯定句。
must do ( 这里的 do 通常是状态动词或系动词 ) ，表示对现在状态的推测。
他肯定很懒，因为他的课桌很不整洁。He must be very lazy for his desk is very untidy
卡罗尔肯定对她的工作厌烦了，她每天都做同样的事。Carol must get very bored with her job, She does the same thing every day
must be doing 表示对现在动作或状态的推测。
多穿点儿衣服，你只穿一件衬衣，肯定觉得冷。Put on more clothes, You must be feeling cold with only a shirt on
must have done 表示对过去的动作或状态的推测。
地面是湿的，昨晚肯定下雨了。The ground is wet, it must have rained last night
我没听见电话铃响，我一定是睡着了。I didn't hear the phone, I must have been asleep
must 表示推测只用于肯定句，否定句和疑问句要用 can， could， 来代替 must 。
他刚吃过午饭，不会饿的。He's just had his lunch, He can't be hungry already
他们刚到这里，不可能认识很多人。They have just arrived here, They can't know many people
莱斯利从我身边走过而没打招呼，他肯定没看见我。Leslie walked past me without speaking, He couldn't have seen me
Leslie walked past me without speaking, He can't have seen me
must 可用来表示根据逻辑推理必然要发生的事，可译为“必然会，总是会”。
我们都会死。We all must die
真相必然会大白的。Truth must be out
冬天到了，春天还会远吗？Winter must be followed by spring
must 有时可用来表示“偏偏”的意思。
为什么偏偏在今天下雨？Why must it rain today
正当我午睡时，偏偏一个学生在这个时候来敲门。When I was taking a nap a student must knock at the door
will 和 would 可用于第二人称疑问句，表示请求和建议等。 would 比 will 委婉客气。
你喝点茶，好吗？Will you have some tea ?
你可以把你的欢乐与我们共享吗？Will you share your happiness with us？
请你把这本书传给最后一排的学生好吗？Would you pass this book to the student in the last row？
Will you， Would you， 表示请求和建议的答复。
是的，请。Yes, please
当然可以。Certainly
当然了。Sure
好啊！All right
对不起，不行。I'm sorry, I can't
不，不行。No, thank you
不，不行。No, I won't
will 和 would 可表示意志、愿望和决心，用于各种人称陈述句。
我愿为你做任何事。I will do anything for you
我永远不会告诉你这个秘密。I will never tell you the secret
不愿看的人眼睛最瞎。None is so blind as those who won't see
他们不让他进去因为他衣着破旧。They would not let him in because he was poorly dressed
will 和 would 可表示某种倾向或习惯性动作。
will 表示现在的习惯动作，
would 表示过去的习惯动作。
他每天晚上都在上网。He will surf the Internet every night
那男孩常常坐在那儿好几个钟头，看着车辆行人通过。The boy will sit there hour after hour looking at the traffic go by
遇见陌生人时他总是很紧张。He would be nervous when he met strangers
课上，他总是问一些蠢问题，他的同学们总是嘲笑他。in class he would ask some silly questions and his classmates would laugh at him
will 可表示固执坚持，这时 will 不可使用' ll 的简略形式。用于非人称主语时，表示物体的固有性质和倾向。
我就要这个工作，没有人可阻止我。I will take the job and no one can stop me
他就是不愿按所吩咐的去做。He won't do what he's told
窗子打不开。The window won't open
这种玻璃在重压下也不会破碎。This glass will not crack under heavy pressure
will 表示将来时间时，不可用于条件状语从句，
will 表示意愿或决心时，可用于条件状语从句。
如果你愿意读这本书，我会把它借给你。If you will read the book I'll lend it to you
如果你愿意把烟戒掉的话，你的健康状况就会好转。If you will give up smoking your health will improve
will 和 would 可表示推论或猜测。
病人一小时前吃的安眠药，现在应该睡着了。The patient took the sleeping pills an hour ago, He will be asleep now
他大约在十点钟离开的家。it would be about ten when he left home
我认为他已告知你此事。I thought he would have told you about it
她回家时可能正在下雨。it would be raining when she went home
Would you like 你愿意吗 表示邀请
do you like 你喜欢吗？ 表示习惯
你喜欢看电影吗？ do you like going to the cinema?
是的，我经常去看电影。 Yes, I go to the cinema a lot
今天晚上去看电影好吗？ Would you like to go to the cinema tonight?
非常乐意。 Yes, I'd love to