神秘的快递家族5电子书:英语语法中有哪些情况下使用主动表被动的？

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主动语态改被动语态的方法 1）将主动语态改为被动语态应注意以下三个方面：①将主动语态的宾语改为被动语态的主语；②将主动语态的谓语动词改为“be＋过去分词”结构；③将主动语态的主语改为介词by之后的宾语，放在谓语动词之后（有时可省略）。 2）含直接宾语和间接宾语的主动语态改为被动语态时有两种情况：①把间接宾语改为被动语态的主语，直接宾语仍保留原位；②把直接宾语改为主动语态的主语，此时，间接宾语前要加介词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）不带to的动词不定式作宾语补足语的主动语态，改为被动语态时不定式前要加to。如： They watched the children sing that morning．→The children were watched to sing that morning． 4）带复合宾语的动词在改为被动语态时，一般把主动语态的宾语改为主语，宾语补足语在被动语态中作主语补足语。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）短语动词是不可分割的整体，改为被动语态时要保持其完整性，介词或副词不可遗漏。如： We must take good care of the young trees．→The young trees must be taken good care of． 6）含有宾语从句的主动结构变为被动结构时，通常用it作为被动结构的先行主语，从句放在句子后面；也可采用另一种形式。可以这样转换为被动结构的动词有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．）