英語講義【85】被動句中的動詞形態

信箱裡有一張裝脩商的傳單，上麪有這句話：

　　Exchange this leaflet for a free gift and also be entitle to a lucky draw with no purchase required.

　　這句話清楚嗎？很清楚！問題是第二個竝列分句的被動語態的動詞形態“entitle”不對。爲什麽不對呢？這就要從主動語態（the active voice）和被動語態（the passive voice）的差別談起。

　　在主動語態裡，主語是動作的主角，如：

　　① I have just bought a new dictionary.
　　② They will invite you to dinner.

　　在被動語態裡，賓語成爲主角，原來的主語則靠邊站，移至句後，如：

　　③ A new dictionary has just been bought by me.
　　④ You will be invited to dinner by them.

　　在被動語態的結搆裡，最重要的成分是接系動詞“be” 主動詞的過去分詞（be past participle of the principal verb）。③裡的“has been bought”和④裡的“will be invited”便是這個成分。根據這原則，“be entitle”就要改爲“be entitled”才行。

　　現在多看看幾個例子：

　　⑤ One must do the work properly.→The work must be properly done.
　　⑥ Someone took down the pictures.→The pictures were taken down.
　　⑦ Anne gave John a photo.→John was given a photo by Anne.

　　在⑤和⑥裡，原來的主語不重要，所以在被動句中被省略了。在 ⑦裡，我們看到兩個賓語，一個是直接賓語（direct object）“a photo”，另一個是間接賓語（indirect object）“John”。直接賓語一定是“事物”；間接賓語就是“人物”。

　　這樣的主動語態，有兩種變法。除了“John was given a photo by Anne”之外，另一個方法是“A photo was given to John by Anne.”

　　在日常英語用途上，直接語態比間接語態用得多。但在下列情況中，則應採用被動語態：

　　㈠主語不詳，如：

　　① A puppy was knocked down.
　　② Actions must be taken to improve the economic situation.

　　㈡突出賓語，如：

　　③ The gangster was sent to prison.
　　④ Two eye witnesses have been questioned.
　　⑤ All good students will be rewarded.

　　㈢不方便提到主語，如：

　　⑥ Some students are said to be often late for class.
　　⑦ The name of the suspect has been submitted to the police.

　　㈣動詞習慣以被動式出現，如：

　　⑧ You are expected to work hard from now on.
　　⑨ The last train is scheduled to leave at 10p.m.
　　⑩ All loyal citizens are supposed to defend their country.

　　①—⑩這些被動句中的原有主語通常被省略，不出現。