怎样改肯定句为否定句|肯定句改否定句
时间：2018-12-24 03:26:18 来源：柠檬阅读网 本文已影响 人 
将肯定改为否定句是句型转换练习中常见的题型之一，怎样改呢？ 1、首先“找”，在句中找be(is,am,are,was,were,助动词或情态动词(will,have,has,had,shall,would,could,can,等)如果有,则在上述词后直接加not。
(1)It will rain the day after tomorrow.
It won"t rain the day after tomorrow.
(2)The children were busy just now.
The children weren"t busy just now.
(3)He has been abroad before.
He hasn"t been abroad before.
2、然后“加”，如果句中没有上述词，则须在动词前加上助动词do,does,did 构成否定句,同时要将原句中的动词变成原形。
(4)His parents bought him a new bike.
His parents didn"t buy him a new bike.
(5)My friend does his homework at home.
My friend doesn"t do his homework at home.
(6)The foreigners speak Chinese here.
The foreigners don"t speak Chinese here.
3、将句中的一些副词(连词)变成反义词，常见的有already→yet;and→or;very much→at all;always→never;often→seldom.
(7)He always stays at home on Sundays.
He never stays at home on Sundays.
4、将句中的一些代词变成其反义词，常见的有all→none;both→neither;everything→nothing;everybody→nobody;both…and→neither…nor.
(8)Both of the twins study in our school.
Neither of the twins studies in our school.
(9)Both jim and Kate have visited the factory.
Neither jim nor Kate has visited the factory.
5、在完成时态中have(has,had)为助动词,构成否定句直接在其后加not,但是如果have(has,had)作实义动词，则在句中需要根据动词形式加适当的助动词do,does,did构成否定句。
(10)They had finished the work by the end of last month.
They hadn"t finished the work by the end of last month.
(11)The students had a meeting after school.
The students didn"t have meeting after school.
6、have(has,had)作“有”讲时，既可以在其后直接加not也可以加助动词do,does,did构成否定。
(12)I have a dictionary
I haven"t a dictionary.或 I don"t have a dictionary.
7、used to do sth“过去常常做……”,可以直接在used后加not 也可以加助动词did构成否定。
(13)He used to live in the country.
He usedn"t to live in the country.或He didn"t use to live in the country.
8、had better do sth.“最好做……”的否定结构为had better not do sth.
(14)You"d better call me in the evening.
You"d better not call me in the evening.
9、动词不定式的否定形式为在to 前加not.（不需要加助动词）。
(15)Will you please keep the windows open?
Will you please notkeep the windows open?
(16)The teacher told us to hand in the homework today.
The teacher told us not to hand in the homework today.但区别：
The teacher didn"t tell us to hand in the homework today.
10、值得一提的是完全否定和不完全否定。
试比较下面两组句子：
(17)Both of his parents aren"t teachers.他父母不都是老师。
(18)Neither of his parents is a teacher.他父母都不是老师。
(19)Everyone doesn"t like to be late.不是每个人都想要迟到。
(20)Nodody likes to be late.每一个人都不想要迟到。
11、must作“必须，应该”讲时，其否定用mustn"t或needn"t，但是作“一定”讲时，其否定用can"t。
(21)You must finish your work before the sun goes down.你们必须在太阳落山之前完成你们的工作。
You needn"t finish your work before the sun goes down.你们没有必要在太阳落山前完成你们的工作。
(22)The man in the white car must be Mr.Green.白色小汽车里的那人一定是格林先生。
The man in the white car can"t be Mr.Green.白色小汽车里的那人不可能是(一定不是)格林先生。
练习将下列句子改为否定句。
1.He read the letter from the granny"s son to her.
2.both of the twins study in our school.
3.The shop must be closed on Sundays.
4.He"d better wait for his turn to buy the ticket.
5.They enjoyed the evening party very much.
6.He"s already cleaned the bedroom.
7.My friend has lunch at school every day.
8.Mrs. Green used to live in the countryside.
9.He can speak both French and English.
10.The little child can dress himself.
11.The teacher will give us a talk next Monday.
12.She flies a kite with her friend.
13.Ann and Kate were at home last night.
14.There are some potatoes and tomatoes in the fridge.
15.We saw something strange in the sky.
16.Jim does housework at home.
参考答案
1.He didn"t read the letter from the granny"s son to her.
2.Neither of the twins studies in our school.
3.The shop can"t be closed on Sunday.
4.He"d better not wait for his turn to buy the ticket.
5.They didn"t enyoy the evening party at all.
6.He hasn"t cleaned the bedroom yet.
7.My friend doesn"t have lunch at school every day.
8.Mrs.Green usedn"t to live in the countryside.或Mrs.Green didn"t use to live in the countryside.
9.He can speak neither French nor English.
10.The little child can"t dress himself.
11.The teacher won"t give us a talk next Monday.
12.She doesn"t fly a kite with her friend.
13.Ann and Kate weren"t at home last night.
14.There aren"t any potatoes or tomatoes in the fridge.或There are no potatoes or tomatoes in the fridge.
15.We saw nothing strange in the sky.或We didn"t see anything strange in the sky.
16.Jim doesn"t do housework at home.
（责任编辑 胡新秀）
