肯定句变否定句0001

1、一、动词be的否定式动词be根据不同的人称和时态可以有 am, is, are, was, were 等不同形式，可 用作连系动词(表示“是”、“在”等)和助动词(用于构成进行时态和被动语态等)， 但不管何种情况，构成否定式时，一律在其后加 n ot。 I ' mold, but you' re young. I ' mnot old, but you' re not young. He was reading and I was writing. He was not reading and I was notwriti ng.二、动词have的否定式动词ha

2、ve根据不同的人称和时态可以有 have, has, had等形式，可以用作实意 动词和助动词，分以下情况讨论。1. 用作实意动词表示状态，如表示拥有、患病或用于 have to表示“必须”等， 在构成否定式时可以直接在其后加 not,也可根据情况在其前使用do n't, does n' t， didn ' t。 He has a car. He hasn' t a car. / He doesn' t have a car. He had somedictionaries. He hadn' t any dictionaries./ He di

3、dn 't have any dicti on aries. You have to go with him. You haven' t to go with him. / You don ' t have to go with him.【注】have to构成否定式时以在其前加don' t等较为常见。2. 用作实意动词表示动作，如表示“吃(二eat) ”、“喝(=drink) ”、“拿(=take) ”、“收到(=receive)、“度过(=spend) ”等，构成否定式时不能直接在其后加not，而应根据情况在其前使用don' t, doesn 

4、9; t, didn ' t 。 He had some cake for breakfast. He didn ' t have any cake for breakfast. We had a good holiday. We didn ' t have a good holiday.3. 用作助动词构成完成时态，其否定式只能在其后加n ot。 I have read the book. I have not read the book. He had left whe n I arrived. He had n' t left whe n I arrive

5、d.三、情态动词的否定式情态动词的否定式一般在其后加not构成。 I can finish the work in an hour. hour.f I can ' t finish the work in an You must go with us. f You mustn' t go with us. We should help them. f We shouldn ' t help them.四、实意动词的否定式一般实意动词的否定式，通常应根据不同时态和人称在实意动词之前加do n' t,doesn' t, didn ' t 等。 He

6、works in a bank.f He does n' t work in a bank. We ofte n hear from her.f We don' t ofte n hear from her. I met her at the station.f I didn ' t meet her at the station.加上does not或did not改为否定句以后，要把原句的动词改为原形动词，特 别是行为动词do的第三人称单数does和过去时did，在主语后面加上does n't 或did n't以后，千万要注意把句中的 does或di

7、d改为do。五、 祈使句的否定结构为：don't十原形动词改为否定句时，要在句首加上 do n't，其它不变，即：Look out of the wi ndow. f Don't look out of the wi ndow六、当陈述句中含有 something这个词时把句子改为否定句有两种方法：其一，在句中相应位置加not，再把something改成 anything ; 其二，直接把 something 改为 nothing 即可。 There is someth ing wrong with the radio.把这个句子改为否定句有两种方法：其一，先把 not

8、力卩在is 后面，再把 something 改为 anything 即：There is not anything wrong with the radio .其二把 something 直接改为 nothing ，即：There is nothing wrong with the radio . I have somethi ng importa nt to tell you .把这个句子变成否定句有两种方法：其中一种方法是先把 not加在have后面，再把something变成anything，即：I have not any thi ng importa nt to tell you.第

9、二种方法是直接把 something 改为 nothing，即：I have nothing importantto tell you七、当陈述句是一个主从复合句而主句的谓语动词是think或believe等时，把这种句子改为否定句，往往是否 定think或believe等而不否定后面从句中的谓语动词，尽管意思是否定从句的 谓语动词。 I thi nk he will be back soon这个复合句中主句的谓语动词是think ，所以在改为否定句时要在think前面加 上 don't，即：I don't think he will be back soon.汉语意思：我认为

10、他不会很快回来。八、某些特殊句型改为否定句时，有不同的方法：1. 在陈述句中含有had better时，要把not加在better后面，动词原形前面。 You had better go with us .把这个句子改为否定句，要把not加在better 之后，g o之前，即：You had better not go with us.千万不要改成： You had not better to go with us .或 Youhad better don't go with us.因为，要否定的是后面的动词不定式短语。同时，had better后面要用动词原形（不带to ）2. 当陈

11、述句中含有both +名词或者both of +名词作主语时，改为否定句时则用neither代替both，并且要注意谓语动词数的变化。 Both of them work in the school library.句子含有both，改为否定句时用neither代替both，同时谓语动词 work改为works，即： Neither of them works in the school library. Both an swers are right .把这个句子改为否定句，用 neither代替both，谓语动词are改为is，即：Neither an swer is right .3.

12、句中含有both . and的肯定句改为否定句时用 neither . nor改写，同 时neither . . nor还可以把两个简单句的否定形式连成一个句子。 Both Mary and Joa n are stude nts把这个句子改为否定句时，通常用 Neither . nor代替Both. . and，同时把 are 改为 is，students 改为 a student 即：Neither Mary nor Joan is a student .4. neither . . nor连接两个主语时，谓语动词决定于nor后面的名词或代词的 单复数形式。 This book is bo

13、th in terest ing and in structive把这个句子改为否定句，用 neither . nor代替both . and,因为连接部分 在句中作表语，所以谓语动词不变，即： This book is neither interesting nor in structive . I don't see that film . He does n't see it either .这两个否定句可以用neither . . nor连成一个句子，谓语动词改为肯定式 see, 人称和数由nor后面的he决定，即：Neither he nor I see that f

14、ilm.，或者把I和he交换.即：Neither I nor he sees that film .这说明谓语的人称 和数由nor后面的靠近谓语的人称和数决定。在把肯定句改为否定句时，注意把 句中的some， 改成any。巩固练习：将下列句子改为否定句1. We do morning exercises every day .Wemorning exercises every day .2. All of us can swim .can swim .Joa n I in Class One4. There is something wrong with my bike .Therewrong

15、 with my bike .5. You may stay here before I come back .Youhere before I come back .6. Read the text after me .the text after me.7 . Li Lei n eeds some help with his En glish.Li Leihelp with his En glish.8 . He said he would g o to Beiji ng the n ext week.Hego to Beijing thenext week .9 . The bike has already bee n m en ded .The bikemended10 . I thi nk it is going to rai n tomorrow.I going to raintomorrow.Key:1 . don't do 2. None of us 3 . Neither ; nor; am 4. is nothing5. must n't stay 6. Don't read 7. does n't n eed any 8. did n't say he would 9 .