英語知識點總結：主動語態(tài)和被動語態(tài)

動作是由主語完成的，要用主動語態(tài)，如：we speak chinese in china.在中國我們說漢語；如果主語是動作的承受者，或者是說動作不是由主語而是由其他人完成的，則用被動語態(tài),如：chinese is spoken by us in china.在中國漢語被我們說。
一、主動語態(tài)改成被動語態(tài)方法　　把主動語態(tài)改為被動語態(tài)非常簡單，可以遵循以下幾個步驟：
1. 將主動語態(tài)的賓語作被動語態(tài)的主語；
2. 謂語動詞變?yōu)椤癰e+及物動詞的過去分詞”，并通過be的變化來表達出不同的時態(tài)；
3主動語態(tài)的主語變?yōu)榻樵~by的賓語，組成介詞短語放在被動結構中的謂語動詞之后。（有時by的短語可以省略）；
例：1. bruce writes a letter every week. →a letter is written by bruce every week.
二、被動語態(tài)的用法：
1. 一般現(xiàn)在時的被動語態(tài)構成：is / am / are + 及物動詞的過去分詞 　　our classroom is cleaned everyday.
2. 一般過去時的被動語態(tài)構成：was / were + 及物動詞的過去分詞 　　a new shop was built last year.
3. 現(xiàn)在完成時的被動語態(tài)構成：has / have + been + 及物動詞的過去分詞 　　this book has been translated into many languages. 　　
4. 一般將來時的被動語態(tài)構成：will+ be + 及物動詞的過去分詞 　　　　many more trees will be planted next year.
5. 含有情態(tài)動詞的被動語態(tài)構成：情態(tài)動詞+ be + 及物動詞的過去分詞 　　young trees must be watered often.
6. 現(xiàn)在進行時的被動語態(tài)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.
7. 不定式的被動語態(tài)：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.
三、使用被動語態(tài)應注意的幾個問題：
1. 不及物動詞無被動語態(tài)。 　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(tài)中不帶to，但變?yōu)楸粍诱Z態(tài)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 　　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(tài)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.
5. 一些動詞短語用于被動語態(tài)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 at him. →he can’t be laughed at by us.