否定句：
表示否定的句子。必须有否定词。
否定句的构成形式：
a. 谓语为be动词时，“be+not "一名学生。
b. 谓语为实义动词而且没有情态动词和助动词时，“do/ does/ did+not"构成否定。 
例：I do not like dancing. 我不喜欢跳舞。 
      He does not want to go to school. 他不想去上学。
c. 谓语为“情态动词+实义动词”时，“情态动词+not”构成否定。 
例：You must not smoke. 你千万不要吸烟。 
       I can not catch it. 我抓不住它。
否定句在英语语法中可以分为九类：
（1）一般否定句
I don't know this. No news is good news.
There is no person（smoking）/not a person/not any person（smoking）in the house.
（2）特指否定
He went to his office, not to see him.
I am sorry for not coming on time.
I don't think/believe/suppose/feel/imagine you are right.
（3）部分否定
All the answers are not right
All is not gold that glitters
I don't know all of them.
I can't see everybody/everything.
Both of them are not right.
（4）全体否定
None of my friends smoke.
I can see nothing/nobody.
Neither of them is right.
Nothing can be so simple as this.
（5）延续否定
You didn't see him, neither/nor did I.
You don't know, I don't know either.
He doesn't know English, let alone/to say nothing of/not to speak of（更不用说）French.
（6）半否定句
We seldom/hardly/scarcely/barely hear such fine singing.
I know little English. I saw few people.
（7）双重否定
You can't make something out of nothing.
What's done cannot be undone.
There is no sweet without sweat.
No gain without pains.
I can't help /keep/ laughing whenever I hear it.
No man is so old but（that）he can learn.
（8）排除否定
Everyone is ready except you.
He did nothing but play.
But for your help, I couldn't do it.
（9）加强否定
I won't do it at all.
I can't see it any more.
He is no longer a boy.

否定转移的形式与用法：
一、动词的否定转移
1.形式上否定主句的谓语，实际上是否定从句的谓语
当动词“think”、“believe”、“suppose”、“imagine”、“expect”、“feel”的主语是第一人称，谓语动词为没有任何副词修饰的一般现在时，它们的否定式实际上是对宾语从句的否定。
表示说话者提出一种委婉的看法或主张。如：
I think that he will help us.——I don’t think that he will help us. 我认为它不会帮助我们。
I believe that he is right.——I don’t believe that he is right. 我认为他不对。
I suppose that he likes it.——I don’t suppose that he likes it. 我想他不喜欢它。

2. 形式上否定谓语动词，实际上否定复合宾语
当动词“think”、“believe”、“suppose”、“imagine”、“expect”、“feel”、“find”的主语是第一人称，谓语动词为没有任何副词修饰的一般现在时，它们前面的否定式实际上是对复合宾语的否定。表示说话者所提出的一种委婉的看法或主张。如：
I think math difficult. — I don’t think math difficult. 我认为数学不难。
I find the story interesting. — I don’t find the story interesting. 我认为这个故事没有趣。
I expect so. —I don’t expect so. 我认为不会。

二、动词“think”、“believe”、“suppose”、“imagine”、“expect”、“feel”在下列情况下，否定不转移：
1.这些动词跟其他另一个动词一起做并列谓语时，否定不转移。如：
I believe and hope he won’t do that. 我相信并且也希望他将不会那样做。
I feel and admit that we are not foolish. 我觉得并且也承认我们并不愚蠢。

2.用于疑问句时，否定不转移。如：
Do you think it is not going to rain? 你认为天不会下雨吗？
Don’t you believe that he has done a good thing? 难道你不相信他做了一件好事？

3.用作插入语时，否定不转移。如：
Li Lei, I think, won’t be angry with you. 我想李蕾不会生你的气。
Tom, I suppose, won’t be against it. 我猜想汤姆不会反对。
Mike, I believe, hasn’t seen the film. 我认为迈克没有看这场电影。

4.动词前有其他副词修饰时，否定不转移。如：
I really don’t think it’s necessary for us to go there now. 我的确不认为我们有必要去那儿。
I feel strongly that he shouldn’t do such a thing. 我强烈地认为他不应该做那样的事。

5.动词为非一般现在时或主语不是第一人称时，否定不转移。
I thought that he wouldn’t come back soon. 我原以为他不会回来得这么快。
She didn’t believe that he became a good boy. 她不相信它变成了一个好孩子。
He thinks that he isn’t fit for the job. 他认为他不适合这件工作。
He doesn’t believe that what we told him is true. 他不相信我们告诉他的事是真的。

6.当宾语从句中含的否定为“not……at all”、“not a little”、“not a few”、“not enough”、“can’t help”等固定搭配时，否定不转移。如：
I think that he doesn’t know it at all. 我想他对那一点也不知道。
I suppose that it is not enough to remember the words if you want to learn the language well. 我认为如果你想把这门语言学好，那么只记单词是不够的。
I believe that you can’t help singing our national anthem when you win the first place in the Olympic Games. 我相信当你在奥运会上获得第一名时你会情不自禁地唱起国歌来。

7.当宾语从句中含“no”、“nothing”、“nobody”、“nowhere”、“hardly”、“seldom”、“little”、“few”等否定词或半否词时，否定不转移。如：
I believe that nothing can make me give it up. 我想任何事情也不能使我放弃。
I think that no one can escape if the ship sinks in the sea. 我认为如果这艘船沉入海底的话，那么谁也逃不掉。
I suppose that he is a man of few words. 我猜想他是一个言语不多的人。