一。概念：

動詞的語態是動詞的一種形式，表示主語和謂語之間語法或語義的關系。英語的語態有兩種：主動語態和被動語態。主動語態用于主動句，表示主語是動作的執行者。被動語態用于被動句，表示主語是動作的承受者。主動語態的構成方式與動詞時態相同，而被動語態由 助動詞be+過去分詞 構成，有人稱，數，時態的變化。

一。 相關知識點精講

1. let 的用法

1)當let后只有一個單音節動詞，變被動語態時，可用不帶to 的不定式。例如：

They let the strange go.他們放陌生人走了。

---> The strange was let go.

2)當let 后賓補較長時，let 通常不用被動語態，而用allow或permit 代替。例如：

The nurse let me go to see my classmate in the hospital. 那護士讓我去探望住院的同學。

----> I was allowed / permitted to see my classmate in the hospital.

2.短語動詞的被動語態

短語動詞是一個整體，不可丟掉后面的介詞或副詞。例如：

My sister will be taken care of by Grandma. 我妹妹由奶奶照顧。

Such a thing has never been heard of before. 這樣的事聞所未聞。

3. 表示“據說”或“相信” 的詞組，基本上由believe, consider, declare, expect, feel , report, say, see, suppose, think, understand等組成。例如：

It is said that… 據說

It is reported that… 據報道

It is believed that…大家相信

It is hoped that…大家希望

It is well known that… 眾所周知

It is thought that…大家認為

It is suggested that…據建議

It is taken granted that… 被視為當然

It has been decided that… 大家決定

It must be remember that… 務必記住的是

4. 不用被動語態的情況

1)不及物動詞或不及物動詞短語，如appear, die disappear, end(vi. 結束), fail, happen, last, lie, remain, sit, spread, stand, break out, come true, fall asleep, keep silence, lose heart, take place等沒有無被動語態。例如：

After the fire, very little remained of my house. 大火過后，我家燒得所剩無幾。

比較：rise, fall, happen是不及物動詞;raise, seat是及物動詞。

要想正確地使用被動語態，就須注意哪些動詞是及物的，哪些是不及物的。特別是一詞多義的動詞往往有兩種用法。解決這一問題唯有在學習過程中多留意積累。

2) 不能用于被動語態的及物動詞或動詞短語，如fit, have, hold, marry, own, wish, cost, notice, watch agree with, arrive at / in, shake hands with, succeed in, suffer from, happen to, take part in, walk into, belong to等。例如：

This key just fits the lock. 這把鑰匙只配這把鎖。

Your story agrees with what had already been heard. 你說的與我們聽說的一致。

3) 系動詞無被動語態，如appear, be become, fall, feel, get, grow, keep, look, remain, seem, smell, sound, stay, taste, turn等。例如：It sounds good. 聽上去不錯。

4) 帶同源賓語的及物動詞如die/death, dream/dream, live/life等，以及反身代詞，相互代詞，不能用于被動語態。例如：

She dreamed a bad dream last night. 她昨晚做了個惡夢。

5) 當賓語是不定式時，很少用于被動語態。例如：

(對) She likes to swim.

(錯) To swim is liked by her.

5. 主動形式表示被動意義

1)wash, clean, cook, iron, look, cut, sell, read, wear, feel, draw, write, sell等。例如：

The book sells well.這本書銷路好。

This knife cuts easily. 這刀子很好用。

2)blame, let(出租), remain, keep, rent, build等。例如：

I was to blame for the accident. 事故發生了，我該受指責。

Much work remains. 還有許多活要干。

3) 在need, require, want, worth (形容詞), deserve后的動名詞必須用主動形式。例如：

The door needs repairing.= The door needs to be repaired. 門該修了。

This book is worth reading.這本書值得一讀。

4)特殊結構：make sb. heard / understood (使別人能聽見/理解自己)等。例如：

Explain it clearly and make yourself understood. 解釋清楚些，讓別人理解你的話。

6. 被動形式表示主動意義，如 be determined, be pleased, be graduated (from), be prepared (for), be occupied (in), get married等。例如：

He is graduated from a famous university. 他畢業于一所有名的大學。

注意：表示同某人結婚，用marry sb. 或get married to sb.均可。例如：

He married a rich girl. 他與一個富妞結婚了。

He got married to a rich girl.

7.need/want/require/worth

當 need, want, require, be worth后面接doing時，表示的是被動意義。例如：

Your hair wants cutting.你的頭發該理了。

The floor requires washing. 地板需要沖洗。