具體用法：
不及物動詞無被動語態。
What will happen in 100 years.
The dinosaurs disappeared about 65 million years ago.
2.有些動詞用主動形式表示被動意義。
This pen writes well.
This new book sells well.
3.感官動詞或使役動詞使用省略to的動詞不定式，主動語態中不帶to ，但變為被動語態時，須加上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.
4.如果是接雙賓語的動詞改為被動語態時，直接賓語(物)作主語，那么動詞后要用介詞，這個介詞是由與其搭配的動詞決定。
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.
5.一些動詞短語用于被動語態時，動詞短語應當看作一個整體，而不能丟掉其中的介詞或副詞。
We can't laugh him. →He can't be laugh by us.
He listens to the radio every day. →The radio is listened to by him every day.
The nurse is taking care of the sick man. →The sick man is being taken care of by the nurse.