被动语态是什么
被动语态是是动词的一种形式，用以说明主语与谓语动词之间的关系，被动语态表示主语是动作的承受者。
一、被动语态介绍
被动语态表示主语是动作的承受者。被动语态是动词的一种特殊形式，一般来说，只有需要动作对象的及物动词才有被动语态。汉语往往用"被""受""给"等被动词来表示被动意义 。被动语态由“助动词be+及物动词的过去分词”构成。被动语态的时态变化只改变be的形式，过去分词部分不变。疑问式和否定式的变化也如此。
二、被动语态构成形式
1.am/is/are +done (过去分词)一般现在时
2.has /have been done现在完成时
3.am/is /are being done现在进行时
4.was/were done一般过去时
5.had been done过去完成时
6.was/were being done过去进行时
7.shall/will be done一般将来时
8.should/would be done过去将来时
9.shall/will have been done将来完成时（少用）
10.should/would have been done过去将来完成时（少用）
三、如何使用被动语态
1.一般现在时的被动语态构成：is / am / are +及物动词的过去分词
Our classroom is cleaned everyday.
I am asked to study hard by my mother.
Knives are used for cutting things.
2.一般过去时的被动语态构成：was / were + 及物动词的过去分词
The new shop was built last year.
Dinosaur eggs were laid long long ago.
3.现在完成时的被动语态构成：has / have + been +及物动词的过去分词
This book has been translated into many languages.
Many man-made satellites have been sent up into space by many countries.
4.一般将来时的被动语态构成：will+ be + 及物动词的过去分词
A new hospital will be built in our city.
Many more trees will be planted next year.
5.含有情态动词的被动语态构成：情态动词+ be + 及物动词的过去分词
Young trees must be watered often.
Your mistakes should be corrected right now.
The door may be locked inside.
Your homework can be handed in tomorrow.
6.现在进行时的被动语态构成：am / is / are + being +及物动词的过去分词
Uncle Wang is mending my bike now.→
My bike is being repaired by Tom now.
They are planting trees over there. →
Trees are being planted over there by them.
7.不定式的被动语态：to + be + 及物动词的过去分词
There are two books to be read. →
There are twenty more trees to be planted.
