1．被動(dòng)語態(tài)的構(gòu)成

由于不及物動(dòng)詞不能帶賓語，故無被動(dòng)語態(tài)，只有及物動(dòng)詞或相當(dāng)于及物動(dòng)詞的動(dòng)詞短語才有被動(dòng)語態(tài)，其基本構(gòu)成方式是“助動(dòng)詞be＋過去分詞”。

注意：“be＋過去分詞”結(jié)構(gòu)不一定都是被動(dòng)語態(tài)，有些動(dòng)詞（如 be，feel，look，seem等）后面的過去分詞已轉(zhuǎn)化為形容詞，用作表語表示狀態(tài)。如：

My bike is broken．（我的自行車壞了。）

The door is open．（門開了。）

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2．主動(dòng)語態(tài)改被動(dòng)語態(tài)的方法

1）將主動(dòng)語態(tài)改為被動(dòng)語態(tài)應(yīng)注意以下三個(gè)方面：①將主動(dòng)語態(tài)的賓語改為被動(dòng)語態(tài)的主語；②將主動(dòng)語態(tài)的謂語動(dòng)詞改為“be＋過去分詞”結(jié)構(gòu)；③將主動(dòng)語態(tài)的主語改為介詞by之后的賓語，放在謂語動(dòng)詞之后（有時(shí)可省略）。

2）含直接賓語和間接賓語的主動(dòng)語態(tài)改為被動(dòng)語態(tài)時(shí)有兩種情況：①把間接賓語改為被動(dòng)語態(tài)的主語，直接賓語仍保留原位；②把直接賓語改為主動(dòng)語態(tài)的主語，此時(shí)，間接賓語前要加介詞to或 for。如：

He gave the boy an apple．→ The boy was given an apple．（或An apple was given to the boy．）

Her father bought her a present．→ She was bought a present by her father．（或A present was bought for her by her father．）

3）不帶to的動(dòng)詞不定式作賓語補(bǔ)足語的主動(dòng)語態(tài)，改為被動(dòng)語態(tài)時(shí)不定式前要加to。如：

They watched the children sing that morning．→ The children were watched to sing that morning．

4）帶復(fù)合賓語的動(dòng)詞在改為被動(dòng)語態(tài)時(shí)，一般把主動(dòng)語態(tài)的賓語改為主語，賓語補(bǔ)足語在被動(dòng)語態(tài)中作主語補(bǔ)足語。如：

We call him Xiao Wang．→ He is called Xiao Wang．

He cut his hair short．→ His hair was cut short．

They told him to help me．→ He was told to help me．

5）短語動(dòng)詞是不可分割的整體，改為被動(dòng)語態(tài)時(shí)要保持其完整性，介詞或副詞不可遺漏。如：

We must take good care of the young trees．→The young trees must be taken good care of．

6）含有賓語從句的主動(dòng)結(jié)構(gòu)變?yōu)楸粍?dòng)結(jié)構(gòu)時(shí)，通常用it作為被動(dòng)結(jié)構(gòu)的先行主語，從句放在句子后面；也可采用另一種形式?？梢赃@樣轉(zhuǎn)換為被動(dòng)結(jié)構(gòu)的動(dòng)詞有know，say，believe，find，think，report等。如：

People believe that he is ill．→It is believed that he is ill．（或：He is believed to be ill．）

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3．被動(dòng)語態(tài)改為主動(dòng)語態(tài)的方法：

被動(dòng)語態(tài)中介詞by后的賓語改為主動(dòng)語態(tài)中的主語（或按題意要求確定主語），按照這個(gè)主語的人稱和數(shù)以及原來的時(shí)態(tài)把謂語動(dòng)詞形式由被動(dòng)語態(tài)改為主動(dòng)語態(tài)。注意在主動(dòng)語態(tài)中有的動(dòng)詞要求不帶to的動(dòng)詞不定式作賓語補(bǔ)足語，此時(shí)要把被動(dòng)語態(tài)中的to去掉。被動(dòng)語態(tài)的主語用來作主動(dòng)語態(tài)的賓語。如：

History is made by the people．→ The people make history．