典型例題
The library needs___, but it’ll have to wait until Sunday.
A. cleaning B. be cleaned C. clean D. being cleaned
答案A. need (實意) +n /to do，need (情態)+ do，當為被動
語態時，還可need + doing. 本題考最後一種用法，選A。如有to
be clean 則也為正確答案。
典：done，"不可能已經"。must not do 不可以（用於一般現在時)。
一、 被動語態的用法：
1. 一般現在時的被動語態構成：is / am / are + 及物動詞的過去分詞
Our classroom is cleaned everyday.
I am asked to study hard.
Knives are used for cutting things.
2. 一般過去時的被動語態構成：was / were + 及物動詞的過去分詞
A new shop was built last year.
Dinosaur eggs were laid long long ago.
3. 現在完成時的被動語態構成：has / have + been + 及物動詞的過去分詞
This book has been translated into many languages.
Many man-made satellites have been sent up into space by many countries.
4. 一般將來時的被動語態構成：will+ be + 及物動詞的過去分詞
A new hospital will be built in our city.
Many more trees will be planted next year.
5. 含有情態動詞的被動語態構成：情態動詞+ be + 及物動詞的過去分詞
Young trees must be watered often.
Your mistakes should be corrected right now.
The door may be locked inside.
Your homework can be handed in tomorrow.
6. 現在進行時的被動語態構成：am / is / are + being + 及物動詞的過去分詞
Uncle Wang is mending my bike now.→
My bike is being repaired by Tom now.
They are planting trees over there. →
Trees are being planted over there by them.
7. 不定式的被動語態：to + be + 及物動詞的過去分詞
There are two books to be read. →
There are twenty more trees to be planted.
二、 怎樣把主動語態改成被動語態?
把主動語態改為被動語態非常簡單，可以遵循以下幾個步驟：
1. 先找出謂語動詞；
2. 再找出謂語動詞後的賓語；
3. 把賓語用作被動語態中的主語；
4. 注意人稱、時態和數的變化。
例：1. Bruce writes a letter every week. →A letter is written by Bruce every week.
2. Li Lei mended the broken bike this morning.→The broken bike was mended by Li Lei this morning.
3. He has written two novels so far.→Two novels have been written by him so far.
4. They will plant ten trees tomorrow.→Ten trees will be planted by them tomorrow.
5. Lucy is writing a letter now.→A letter is being written by Lucy now.
6. You must lock the door when you leave.→the door must be locked when you leave.
三、 使用被動語態應注意的幾個問題：
1. 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，那么動詞後要用介詞，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. 一些動詞短語用於被動語態時，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.
中間語態
某些語言(比如梵語、冰島語和古希臘語)有中間語態。中間語態在主動語態和被動語態的中間，因為主語不能被歸類為主動者或被動者但有二者的要素。表現得主動但表達被動行動的不及物動詞刻畫了英語中的中間語態。例如，在“The casserole cooked in the oven”，cooked 在語法上主動但在語義上被動，屬於中間語態。在古希臘語中，中間語態經常是反身的，指示主語做關於自身或為了自身的行動，比如“The boy washes himself”或“The boy washes”。它可以是及物動詞也可以是不及物動詞。它偶爾用在使役性意義上，比如“The father causes his son to be set free”或“The father ransoms his son”。
拉丁語中的很多異相動詞代表了倖存的原始印歐語中間語態；其中很多在羅曼語言如法語和西班牙語中倖存為強制性偽-反身動詞。
被動語態
拉丁語
拉丁語的被動表現完全符合屈折語的特徵，即採用動詞的一個特定變形（inflection）。例如：“poemam legit” 他讀詩歌。“poema legitur”詩歌被他讀。
英語
屈折特徵已經退化的英語使用迂迴方式表現被動態。也就是並非利用動詞的某一形式來表現被動，而是使用若干辭彙的組合來形成被動態表現。具體地說，是由 be 助動詞和主動詞的過去分詞組合而成。
漢語
參見：把字句、被字句及主謂短語
漢語對被動態的使用具有兩個特徵：1，作為孤立語，單純地使用主賓易位和助詞“被”來實現被動；2，作為主題優勢語言，漢語對被動態的使用相對於印歐語言比較謹慎。例文： 主動：狗咬了這個男人。 被動：這個男人被狗咬了。
日語
日語使用黏著的方式，通過在動詞後附著被動助動詞“れる･られる”（現代日語）或“る”（古典日語）來表現被動。但是由於日語也是主題優勢語言，賓語出現在一個語法上為主動句的主語位置的情況也經常能見到。另外，日語還存在一種稱為受害態的特殊被動表現。
