被动语态的用法
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.
2. 一般过去时的被动语态构成：was / were + 及物动词的过去分词
A new shop was built last year.
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.
4. 一般将来时的被动语态构成：will+ be + 及物动词的过去分词
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.
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 Tomnow.
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 tobe planted.