Just as I went to the gate,I surprisingly found that a boy o

很简单啊,你只要记住被动语态后面加过去分词,而主动语态不用,并且被动语态的句子是过去时,主动语态是现在时. 被动语态和主动语态的结构式主动语态是表示主语是谓语动作的使动方的语态.在主动语态中,谓语的动作源自主语,而施加于宾语.相反,在被动语态中,主语是谓语动作的受动方.在主动语态中,主语后面接人（be +动词原型）被动语态（be+动词过去分词）在主动语态中,主语是谓语动词的使动方.在被动语态中,主语是谓语动词的受动方.　在语法结构上,主动语态和被动语态的区别主要在于,主动语态直接使用动词原形作为谓语,然后再在该动词原形的基础上施加时态和其他语法；而被动语态则使用系词+动词的过去分词作为谓语,各种时态和其他语法也施加在系词上.举例：1.主动语态：The snowslide killed him. 雪崩害死了他.被动语态：He was killed by the snowslide. 他死于雪崩.　　2.主动语态：We use electricity to run machines. 我们用电力来开动机器.被动语态：Electricity is used to run machines. 电力被我们用来开动机器.　3.主动语态：Bell invented the telephone in 1876.贝尔于1876年发明了电话.被动语态：The telephone was invented by Bell in1876.电话是贝尔于1876年发明的.注意：
1)wash, clean, cook, iron, look, cut, sell, read, wear, feel, draw, write, sell, drive…The book sells well. 这本书销路好.This knife cuts easily. 这刀子很好用.2)blame, lent(出租), remain, keep, rent, buildI was to blame for the accident. 我对这起事故负责.Much work remains. 还有大量工作要做.3) 在need, require, want, worth (形容词), deserve后的动名词必须用主动形式.The door needs repairing.= The door needs to be repaired. 门需要修了.This room needs cleaning. 这房间应该打扫一下.This book is worth reading. 这本书值得一读.4) 特殊结构：make sb. heard / understood (使别人能听见/理解自己),have sth. done ( 要某人做某事).