剑桥KET语法全概括（6）have to/must+主语代词/宾语代词的用法

1. have to/must

• have to和must的意思都是：必须

        I have to get up at 7.

        I don't have to get up at 7.

        You must come with me.

        You mustn't come with me.

• have to与must的区别：二者的区别非常微小，可以相互替代。如果一定要找出区别，那么have to更倾向于指因外部的要求而必须做的事情，must更多是指因内部要求而必须做的事情。比如：I have to take my medicine twice a day.（每天吃两次药，来自医生的要求）I must study hard.（好好学习，来自自己的要求）

• 当我们需要用过去式时，就必须要用have to的过去式had to，而不能用mustI had to be ready by the end of the day yesterday.

• must的过去式是must have，但must have的意思不是“必须”，而是对过去的一种猜测He must have read this book before.（他以前肯定读过这本书）

2. 主语代词/宾语代词

• 在英语中代词有主语代词与宾语代词之分

• 主语代词：I, we, you, he, she, it, they

• 与主语代词相对的宾语代词是：me, us, you, him, her, it, themI do not like him.She is working with them.

• 做一做下面的练习：

• A: He / Him ’s a great basketball player. B: I don’t like he / him at all.

• A:  The children are tired. Can you put they / them to bed?B: Where are they / them?

• A: Where’s mum? I can’t see she / her.B: There she / her is!

• A:  We / Us can’t do this homework. Can you help we / us?B:  Daniel is good at Maths. Why don’t you ask he / him?

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剑桥KET语法全概括（1）一般现在时+频率副词

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