should 和could 的区别.在You should.和You could.句型中什么时候用should 什么时候用could在线等鄙视！Ctrl-c,Ctrl-v.

should 和could 的区别.在You should.和You could.句型中什么时候用should 什么时候用could在线等鄙视！Ctrl-c,Ctrl-v.
should 和could 的区别.在You should.和You could.句型中什么时候用should 什么时候用could在线等
鄙视！Ctrl-c,Ctrl-v.

should 和could 的区别.在You should.和You could.句型中什么时候用should 什么时候用could在线等鄙视！Ctrl-c,Ctrl-v.
You should 表示你应该做某事 you could 表示的是你能做某事 作为you can 的过去式
1.can (could)
1）表示能力,could主要指过去时间.
Two eyes can see more than one.两只眼比一只眼看得清.
Could the girl read before she went to school?这女孩上学前能识字吗?
2）表示可能（理论上或是逻辑判断上）.
The temperature can fall to –60℃,that is 60℃ below freezing.
气温可降至—60℃,也就是零下60℃.
He can´t (couldn´t) have enough money for a new car.他不可能有足够的钱买新车.
You mustn´t smoke while you´re walking around in the wood.You could start a fire.
在林子里走时勿吸烟,那样可能会引起火灾.
3）表示允许.
Can I have a look at your new pen?我可以看一看你的新钢笔吗?
He asked whether he could take the book out of the reading—room.
他问他可不可以把书带出阅览室.
4）表惊异、怀疑、不相信等态度.主要用于否定句、疑问句或感叹句中.
Where can (could) they have gone to?他们会去哪儿了呢?
He can´t (couldn´t) be over sixty.他不可能超过六十岁.
How can you be so careless?你怎么这么粗心?
5）比较委婉客气地提出问题或陈述看法.
Can (Could) you lend me a hand?帮我一把好吗?
I´m afraid we couldn´t give you an answer today.恐怕我们今天不能给你答复.
should
1）表义务.意为“应该”（某件事宜于做）,用于各种人称.
You should be polite to your teachers.你对老师应该有礼貌.
You shouldn´t waste any time.你不应该浪费时间.
2）表推测,意为“想必一定、照说应该、估计”等.
The film should be very good as it is starring first—class actors.
这部新电影是一流演员主演的,估计拍得很好.
They should be home by now.照说他们现在应当已经到家了.
情态动词后跟完成式和进行式的用法
1.情态动词后跟完成式,表“应当已经……”,“想必已经……”,“本来可以……”等意.
I should have finished the work earlier.我应当早一点完成这项工作的.
He isn´t here.He must have missed the train.他还未到,一定是没赶上火车.
Where can (could) he have gone?他能到那里去了呢?
You may (might) have read about it.你可能在报上已经读到这件事了.
You could (might) have been more careful.你本来可以更细心的.
He needn´t have worried about it.他本不必为此事担心.
There was a lot of fun at yesterday´s party.You ought to have come,but why didn´t you?
昨天的聚会非常有意思.你本应该来,为何不来呢?
2.情态动词后跟进行式,表示“想必正在……”,“可能正在……”,“应当正在”等意.
It´s twelve o´clock.They must be having lunch.现在是十二点.他们一定正在吃饭.
They may be discussing this problem.他们可能正在论讨这个问题.
He can´t be telling the truth.他说的不可能是真话.
She shouldn´t be working like that.She´s still so weak.她不应当那样干,她身体仍那么虚.
用在过去时中,could经常表示能够做某事,事实上不一定去做,He could swim across the English Channel.But he didn´t feel like it that day.
他能游过英吉利海峡,但那天他不想游.