be动词,情态动词,助动词do

1、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

2、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

3、句的动词三单式都要变回原型。playdo playsdoes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' pt l'ay football after school.画线提问 : 对 the

4、y/he 提问 : Who plays football after school对 play football 提问: What do they do after schoolWhat 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：know the answer.（一般疑问句） the answer can see some birds.一般疑问句）see birdsdesig ns clothes.一 般疑问句） he

5、clothesare some flowers on the teachers一般疑问.句）deskflowers on the teachersare some apples on the tree.否定句）Thereapp les on the tree.think he is very old.（否定句）Ithi nk hevery old.colour it gree n.（否定句）colour it gree n.doctors are helpful.（变否定句）may have some hot dogs.一般疑问句）aren ' t any pears in the b

6、o同义句）There arep ears in the box.sign means “ No smoking ”Whatthis sig nlooks you ng.（改一般疑问句）sheyoungis you ng.（改为一般疑问句）pencils are in the pencil-box.对划线部分提问）your pen cilsget up at six every day.对划线部分提问）you get up every daylike to walk home.（改为一般疑问句）theyare cars.（用 buses改写成选择疑问句）Are these carsp la nt

7、 is one month old.（就划线部分提问）plantboys are in our house.改为 there be 句型）two boys in our house.plant has two green leaves.pla ntLi goes to Hong Kong by plan e.（同义句）Miss LiHong Kong.22. The women work in the shoe factory.（就戈U线部分提问）wome nis happy, because he is going to take a trip tomorrow.（就戈卩线部分提问）fath

8、er can cook the meals.（就划线部分提问） father 25. You should add water often.（般疑问句） water ofte n、变否定句时相关词的改变肯定句变否定句时， 除将谓语变为否定式外， 句中其他词语也可能随之改变， 女口将 some 改为 any, too 和 also 改为 either, already 改为 yet, and 改为 or 等：There are some birds in the tree. 树上有些鸟。TThere aren ' t any birds in thee. 树上没有鸟。He likes t

9、he girl, too. 他也喜欢这个女孩。T He does n' t like the girl, either他 也不喜欢这个女孩。We have already seen the film. 我们已看过这部电影。TWe have not seen the film yet. 我们没有看这部电影。He likes si ngi ng and dancin g.他喜欢唱歌和跳舞。THe doesn' t like singingr odancing. 他不喜欢唱歌也不喜欢跳舞。 二、部分否定与完全否定比较以下句子：All of us laughed when we heard it. 听到这事时我们都笑了。（肯定句 ）All of us didn t laughed whe n we hea听到这事时我们并未都笑。（部分否 定）Not all of us laughed when we heard it. 听到这事时我们并未都笑。 （部分否定） None of us laughed when we