（4）否定句（Negatives）

肯定句	否定句
（1）I tell a lie.	I do not tell a lie.
（2）I have a book.	I have not a book. I do not have a book.（美）
（3）I am a student.	I am not a student.
（4）I can speak English.	I can not speak English.

例（1）表示凡无助动词的肯定句变为否定句时，须补上助动词 do，然后在 do 后加上 not。但用 never 时，则不需加 do。

例（2）和（3）表示 have 和 be 两动词，其否定句可不用助动词，只将 not 放在它们之后即可。

have 用 do 来构成否定句，系美国的用法。

例（4）表示凡有助动词的肯定句变为否定句时，只在第一个助动词之后加上 not 即可。

英文中只有十二个动词或助动词，not 可放在其后，兹举出以供参考：have、be、do、shall、will、can、may、must、ought、need、dare、used。

但其中 do 用为动词时，则与一般动词同，须用 do 来构成否定，如“Why don’t you do it？”。need 和 dare 亦然，如“I don’t need any more help now. ”，“I didn’t dare to go. ”。又，used not 之缩短形为 usen’t 或 usedn’t（d 不发音）。

注意：（1）用 never 来构成否定句时，则不需用 do。如“I never tell a lie. ”neither...nor 之时亦同，如“I like neither this nor that. ”。

（2）一切命令句，不论何种动词，概用 do not（don’t）来构成否定句，如“Don’t be silly！”“Do not go！”等。

（3）have to（= must）的否定形为 do not have to，绝不可误为 have not to。

（4）不定词及分词之否定形：将 not 放在前，如“to be or not to be”；“not knowing，I cannot cry. ”。

练习题（10）

A. 用 not 于适当的地方，变下列句子为否定句：

1. He has gone out of town.

2. They will be in class tomorrow.

3. I can meet you tonight.

4. I may be able to go with you.

5. We are going to the seashore on our vacation.

6. He will leave on the five o’clock train.

7. He is an engineer.

8. Mr. Smith has studied English for a long time.

9. You must write your exercise in pencil.

10. Mary is taking lessons from Miss Reese.

11. He will be here at five o’clock.

12. I have finished writing my exercise.

13. He is making much progress.

14. We shall see you tomorrow.

15. John used to study hard.

16. I dare ask him.

17. Mary will be promoted to the next class.

18. He has been in class since last month.

19. You ought to go.

20. I have a good library.

21. He is a man of honor.

B. 将下列句子变为否定句：

1. I felt much surprised at what I saw.

2. You sang better yesterday than today.

3. We heard of your success from your father.

4. It rained hard at twelve o’clock.

5. The sun rose at six o’clock this morning.

6. The fox fell into the trap last night.

7. The bees gathered much honey from those flowers.

8. This tree strikes its roots deep into the ground.

9. Some trees die before they are a hundred years old.

10. They told the boy to keep watch over the flock.

11. He strove to do his very best in his new class.

12. He gave as much as sixpence for that little book.

13. John made many mistakes in his examination.

14. It rains every day in New York.

15. I had time to study my lesson last night.

16. I understood everything he said.

17. He eats his lunch at twelve o’clock.

18. She wants to learn English.

19. He began his new work on the fifteenth.

20. Our classroom has three windows in it.

21. I am afraid in the dark.

22. He stayed in Taipei for a long time.

23. We need a rag in our room.

24. We use many books during our lesson.

25. John came to class ten minutes late.

26. Mary likes to study French.

27. They moved to Taichung.

28. William speaks English well.

C. 将下列否定句改为肯定句：

1. He did not see me secretly entering the room.

2. The sun does not rise at five o’clock.

3. The watchman did not run away from the thief.

4. We did not think John to be as clever as James.

5. He did not speak about the coldness of the classroom.

6. She does not think that a complaint should be made.

7. He did not feel ill during his absence from home.

8. The lightning did not strike the top of the house.

9. The noise in the street did not break my sleep.

10. He does not come here in time for his dinner.

11. They did not seek for the lamb that had been lost.

12. The dog did not hunt the deer without success.

13. The master does not expect me to finish this all at once.

14. This book does not seem to be as interesting as that.

15. He did not hear，I think，all that I said to him.

16. The child，walking along the bank，did not fall into the river.

17. This student did not strive to keep at the head of the class.

18. Bees do not gather much honey from these flowers.

19. I will not give this man any money.