新概念英语在线课程

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must 表示必须，是主观上觉得应该做，have to是不得不，是由于客观条件逼迫的必要要做

must 只能用在表示现在和将来的句子里，而have to do可以用在任何时态

3)must, may, might表示猜测：

· must do 表示对现在事实的猜测

·must have done表示对过去事实的猜测

·must have been doing 表示对过去正在进行的事实的猜测

·may/might do, may/might have done表示没有任何事实依据的猜测，might的可能性更小。

5·can’t/couldn’t 表示不可能

need用法

need 用法：

·表示“需要”时为实意动词，后面可以加名词，也可以加不定式：

I need a pen. Do you need any beer? No, I don’t.

I need to have a rest.

·Need doing=need to be done，表示被动

The flowers need watering.

·Need在否定时做情态动词使用

You needn’t go so early. =You don’t need to go so early.

Must I clean the desk right now? No, you needn’t.

不定代词及不定副词

不定代词及不定副词：

·Some any no every

·thing something anything nothing everything

·one someone anyone anything everyone

·where somewhere anywhere anywhere everywhere

·body somebody anybody nobody everybody

1)I looked for my book everywhere, but I can’t find it anywhere.

2)If you want go somewhere, if you want to be someone, you must wake up.

3)Help! Somebody? Anybody?

4)You are really something.

5)Since everybody is here, let’s begin our class.

6)Where did you go? I went nowhere.

7)Nobody is at home.

8)I have nothing left.

感叹句

感叹句：

1) What 名词 主语 谓语

What a beautiful girl she is!

2) How 形容词 主语 谓语

How beautiful the girl is!

祈使句

祈使句：

· 第二人称：

let 其他人称代词

· 祈使句的否定，加don’t

· 反意疑问

祈使句(第二人称)

祈使句表示请求，命令，建议，邀请等，谓语动词一律用原型，句子中通常不用主语，句末用惊叹好或者句号，用降调。

★肯定句 动词原型

例， Come here, please. Go downstairs, please. Stand up. Sit down. Be quiet. Be careful.

祈使句中如果有唤语，一定要用逗号隔开，放在句首或者句尾

Come in, Amy.

Sit down here, Tom.

Mary, give me a book please.

★否定：Don't 动词原型

Don't come here