今天我们继续语法知识啦，相信很多小伙伴都有点疑惑Should/could/Would这三个情态动词到底是怎么区分的呢？那接下来咱们就跟着老师一起来逐个解析哦。
这几个情态动词又称为 “modals of lost opportunity” 因为它们指说话人但愿过去实情不同。
要掌握这几个情态动词的现在完成式
1
首先我们复习一下，情态动词should, could, would的一般规律
1.Should 表建议 (advice)
-
If you want to lose weight, you should eat healthy food.
如果你想减肥，你应该吃健康的食物。
-
You shouldn’t spend so much time watching TV.
你不应该花这么多时间看电视。
-
My tooth has been hurting for a week already.
---You should go to the dentist.
2.Could 表可能性 (possibility)
-
I have the day off tomorrow.
明天我放假。
-
Great! We could spend the day at the beach. Or we could go shopping.
太棒了！我们那天可以去海边。或者去逛街。
-
Could I use your phone, please?（礼貌用语）
请让我用一下你的电话可以吗？
3.Would 表假设意愿 (willingness)
-
If she had more time, she would spend it with her children.
如果她有更多的时间，她会和孩子们一起度过的。
-
They would make a lot of changes if they had enough money.
如果他们有足够的钱，他们会做出很多改变。
经常用语提建议
-
Would you like anything to eat?
-
Would you like to see some new pictures?
同样的规律也适用于should have, could have, and would have。
2
表示对于过去的假设
1.Should Have
过去情况的假设，并且也表示“我应该......”，即“过去那个时候，我应该......”
-
I should have left my house earlier.
我该早点出门。
-
I shouldn’t have yelled at you yesterday. I’m sorry.
我昨天不该吵你吼。对不起。
-
You should have studied. You shouldn’t have played video games all weekend.
你该学习。你不应该整个周末都玩电子游戏。
2.Could Have done
用于描述可能性。即“过去如果怎样/不怎样，现在情况可能有所不同。”
（1）是一种虚拟语气的用法，条件从句是过去完成时，主句could 现在完成时
If I had gone to college, I could have gotten a better job.
如果我上了大学的话，我可能会找到了更好的工作。
（2）Could have 一般与 “if 过去完成时” (If I had gone)连用-这里的条件句是一种虚拟语气的用法。
She could not have been on that flight because I just saw her at work.
她不可能
（3）有时候，could have 也可不接条件句，单独出现。
Are you crazy? We could have gotten into an accident.
3.Would Have
表示对于过去的一种假设。即“过去某种情况可能会不同。” 也经常与表示虚拟if条件句连用。
I would have called, but there was no phone service.
我本来要打电话的，但是没有信号。
I would have loaned you the money, but I didn’t have any.
我本来要借钱给你的，但是我当时没钱。
If we had arrived earlier, we would have caught our flight.
如果我们早点到，我们就赶上飞机了。
4.Would have 比could have 更确定
If I had worked harder,I could have gotten a promotion.
如果我之前工作努力点儿，我可能就升职了。
I got a 58 on the test. If I had gotten two more points, I would have passed.
我考了58分。如果我多考两份，我就通过了。
接下来就是练习环节啦，赶紧来检测下吧：
1. I was really anxious about you. You_________have left home without a word.
2. — I’ll tell Mary about her new job tomorrow.
— You________ have told her last week.
3.I _______ have been more than six years old when the accident happened.
4.If you didn't call me ,I _______have finished my work.
点击下方【阅读原文】
有一个超级大大大大的惊喜哦~
快点快点~记得点赞给小编更多动力哟~~
