③短语动词变被动语态时，勿要掉"尾巴"。

　　The children were taken good care of (by her).

　　Your pronunciation and spelling should be paid attention to.

　　④情态动词和be going to、be to、be sure to、used to、have to、had better等结构变被动语态，只需将它们后面的动词原形变为be +过去分词。

　　⑤当句子的谓语为say、believe、expect、think、know、write、consider、report等时，被动语态有两种形式：（A）谓语动词用被动语态，动词不定式作主补。（B）用it作形式主语，真正的主语在后面用主语在后面用主语从句来表示。如：

　　People say he is a smart boy.

　　It is said that he is a smart boy.

　　He is said to be a smart boy.

　　People know paper was made in China first.

　　It is known that paper was made in China first.

　　Paper was known to be made in China first.

　　类似句型有：It is said / known / suggested / believed / hoped/ thought that ...

（2）不能用被动语态的几种情况。

　　①所有的不及物动词或不及物动词词组不能用于被动语态之中。

　　②表示状态的谓语动词，如：last、hold、benefit、contain、equal、fit、join、mean、last、look like、consist to等。

　　③表示归属的动词，如have、own、belong to等。

　　④表示"希望、意图"的动词，如：wish、want、hope、like、love、hate等。

　　⑤宾语是反身代词或相互代词时谓语动词用主动语态，不能用被动语态。

　　⑥宾语是同源宾语，不定式、动名词等谓语动词不用被动语态。

　　⑦有些动词以其主动形式表示被动意义，特别是当主语是物时，常见的动词有sell、write、wash、open、lock等。

（3）主动形式表被动意义。

　　①当feel、look、smell、taste、sound等后面接形容词时；当cut、read、sell、wear、write等词带状语修饰语时；当动词表示"开始、结束、关、停、转、启动"等意义时。

　　This kind of cloth washes easily.这种布易洗。

　　These novels won't sell well.这些小说不畅销。

　　My pen writes smoothly.我的钢笔写起来很流畅。

　　The door won't lock.门锁不上。

　　The fish smells good.鱼闻起来香。

　　②当break out、take place、shut off、turn off、work out等动词表示"发生、关闭、制定"等意思时。

　　The plan worked out successfully.

　　The lamps on the wall turn off.

　　③want, require, need后面的动名词用主动表示被动含义。

　　④be worth doing用主动形式表示被动含义。

　　⑤在"be + 形容词 + to do"中，不定式的逻辑宾语是句子的主语，用主动代被动。

　　This kind of water isn't fit to drink.

　　The girl isn't easy to get along with.

　　另外：be to blame(受谴责)，be to rent（出租）也用主动形式表被动。

（4）被动形式表示主动意义的几种情况。