小学英语语法情态动词should 及其否定式 shouldn’t

小学英语语法情态动词should 及其否定式 shouldn’t的用法

目前我们学过的情态动词有can(could).may(might),will(would),shall(should), have o(had to).must 等，情态动词无人称和数的变化，不能单独使用，必须与其后的动词原形构成谓语。情态动词should的用法是本单元的重点。

句子结构:should 意思是“应该、应当”，其句子结构是:,肯定句:主语+should+动词原形+其它部分。如:

we should keep quiet in the library. 我们在图书馆应该保持安静。

He should take some medicine at home. 他应该在家吃点药。

They should park their bikes under the tree. 他们应该把自行车停在树下。

2.否定句:主语+shouldn't+动词原形+其它部分。如:

We shouldn't make noise in the library. 我们在图书馆不应该发出声音。

He shouldn't take any medicine at home.他不应该在家吃药。

They shouldn't park their bikes under the tree. 他们不应该把自行车停在树下。

另外，由shouldn't引导的否定句，我们也可以用Don't 开头的否定祈使句来表达，区别是:Don't开头的否定祈使句语气更强烈。如:

You shouldn't eat or drink in the reading room. 你不应该在阅览室里吃喝。同义句: Don't eat or drink in the reading room. 在阅览室里不要吃喝。

3.一般疑问句:Should+主语+动词原形+其它部分。如:

Should you keep quiet in the library? 你们在图书馆应该保持安静吗?

Should he take any medicine at home? 他应该在家吃点药吗?

Should they park their bikes under the tree? 他们应该把自行车停在树下吗?

4. 特殊疑问句:特殊疑问词+should+主语+动词原形+其它部分。如:

What should we do in the library? 我们在图书馆应该做什么?

What should he not do at home? 他在家不应该做什么?

Where should they park their bikes? 他们应该把自行车停在哪里?

二、should与must的区别

should 和 must 都表示建议和要求。从语气上来说，must更强烈，should 更多的是表示建议、意见，而must则表示命令，要求对方必须做到。如:

You should keep the room clcan. 你应该保持室内清洁。

You must keep the room clean. 你必须保持室内清洁。

You should go to school early. 你应该早点到学校。

You must go to school early. 你必须早点到学校。

他们还都可以表示推测，只是相比较起来，must 在表示推测的时候，语气是较肯定的， should 还会出现在一些虚拟语气中。

情态动词 should练习

一、要求改写下列句子。

1. We should move some factories away from our city.

①否定句:

② 一般疑问句:

③ 对划线部分提问:

should eat a lot of vegetables to keep healthy.

①否定句:

② 一般疑问句:

③对划线部分提问:

3. They should be careful in the forest.

① 否定句:

② 一般疑问句:

③ 对划线部分提问:

4. We should eat much in the morning.

① 否定句:

② 一般疑问句:

③ 对划线部分提问:

5. Tom should run in the playground.

① 否定句:

② 一般疑问句:

③对划线部分提问:

二、用括号中所给词的适当形式填空。

1. Dad is sleeping. You shouldn't______(cry) so loudly.

's late. We should_______(take) a taxi at once.

3. To keep the river clean,we shouldn't_________(throw) rubbish in it.

4.- How can we protect the Earth?

-We______(should) save _______(should) waste water.

5,The floor is wet. You_____(should) be careful.

6. Look at that man. He is_____(smoke). He shouldn’t____(smoke) in the

restaurant

't______(shout).We shouldn't_____(make) noise in the theatre.

We should_______(keep) quiet in public places.

always_______(throw) banana skins on the ground. He

should______(put) them in the bin.

should________(keep)quiet in the library.

shouldn't________(speak) loudly in the hospital.

情态动词should练习答案

shouldn't move any factories away from our city.

Should we move any factories away from our city?

What should we do?

shouldn't eat a lot of vegetables to keep healthy.

Should Billy eat a lot of vegetables to keep healthy?

What should Billy do to keep healthy?

shouldn't be careful in the forest.

Should they be careful in the forest?

Who should be careful in the forest?

shouldn't eat much in the morning

Should we eat much in the morning?

When should we eat much?

shouldn'trun in the playground.

Should Tom run in the playground?

Where should Tomrun?

二、 ,shouldn'g,smoke

,make,,put9keep