be动词，情态动词，助动词do/does的用法区别及练习
1. 由连系am，is，are构成的句子：变一般疑问句时把am，is，are提到句子的前面，句尾用问号即可。变否定句时直接在am，is，are后面加not即可。例如：
肯定句:He is a student.
一般疑问句: Is he a student?
否定句: He is not a student.
画线提问: 对he提问: Who is a student?
对 a student 提问: What is he? or What does he do?
2. 由情态动词can, may, should等构成的句子: 变一般疑问句时把can,may,提到句子的前面,句尾用问号即可.变否定句时直接在can,may,后面加not即可. 例如:
肯定句: She can swim.
一般疑问句: Can she swim?
否定句: She can not swim.
画线提问: 对she提问: Who can swim?
对swim提问: What can she do？
3. 由行为动词构成的句子: 需要加助词do或does. 变一般疑问句时把do/does 放在句子前面. 变否定句时把don’t/doesn’t放在动词的前面。要注意观察动词的形式并对号入座。一般疑问句和否定句的动词三单式都要变回原型。
play-----do plays-----does
例如:
肯定句: They play football after school. He plays football after school. 一般疑问句: Do they play football after school? Does he play football after school?
否定句: They don't (do not) play football after school. He doesn’t’ play football after school.
画线提问: 对they/he提问: Who plays football after school?
对play football提问: What do they do after school? What does he do after school?
对after school提问: When do they play football? When does he play football?
针对性练习
按要求改写句子：
1. I know the answer.(一般疑问句)
______ ______ __________the answer?
2. We can see some birds.(一般疑问句)
______ ______ see ______ birds?
3. He designs clothes.(一般疑问句)
______ he ________ clothes?
4. There are some flowers on the teachers’ desk.(一般疑问句) ______ ______ ______ flowers on the teachers’ desk?
5. There are some apples on the tree.(否定句)
There ______ ______ ______ apples on the tree.
6. I think he is very old.(否定句)
I ______ think he ______ very old.
7. Please colour it green.(否定句)
______ ______ colour it green.
8. These doctors are helpful.(变否定句)
______ _______ ______ __________.
9. You may have some hot dogs.(一般疑问句)
_______ ______ ______ ______ ________?.
10. There aren’t any pears in the box.(同义句)
There are ______ pears in the box.
11.This sign means “No smoking”.
What ______ this sign _________?
12. She looks young. （改一般疑问句）
________ she _______ young?
13. She is young.（改为一般疑问句）
______ ______ ____________?
14. My pencils are in the pencil-box.(对划线部分提问)
______ ______ your pencils?
15. I get up at six every day.(对划线部分提问)
______ ______ __________ you get up every day?
16. They like to walk home.(改为一般疑问句)
______ they ________ _______ _______ _________?
17. These are cars.(用buses改写成选择疑问句)
Are these cars______ ______ ?
18. My plant is one month old.(就划线部分提问)
_______ ______ ______ _______ plant?
19. Two boys are in our house.(改为there be句型)
______ ______ two boys in our house.
20.My plant has two green leaves.
_______ ______ _______ ______ ______ _______plant __________?
21. Miss Li goes to Hong Kong by plane.（同义句）
Miss Li ________ _________ Hong Kong.
22. The women work in the shoe factory.（就划线部分提问）
_______ _______ ______ women __________?
23. He is happy, because he is going to take a trip tomorrow.（就划线部分提问）
_______ _______ ______ _________?
24. My father can cook the meals.（就划线部分提问）
_______ ________ ________ father __________?
