for to by指令的用法

一、用to

感官动词或使役动词使用省略to的动词不定式，主动语态中不带to ，但变为被动语态时，须加上to .

例：make somebody do something→somebody+ be +made to do something

see somebody do something→somebody +be +seen to do something

A girl saw my wallet drop when she passed by.→My wallet was seen to drop by a girl when she passed by.

The boss made the little boy do heavy work.→The little boy was made to do heavy work by the boss.

如果是接双宾语的动词改为被动语态时，直接宾语(物)作主语，那么动词后要用介词，这个介词是由与其搭配的动词决定.

He gave me a book.→A book was given to me by him.

He showed me a ticket.→A ticket was shown to me by him.

My father bought me a new bike.→A new bike was bought for me by my father.

二、用by

把主动语态中的主语放在介词by之后作宾语，将主格改为宾格。

例如：All the people laughed at him.=He was laughed at by all people.

They make the bikes in the factory.=The bikes are made by them in the factory.

记忆歌诀：

宾变主，主变宾，by短语后面跟。

三、在主动语态和被动语态用法一样。

谓语动词变被动，be后“过分”来使用