【正文】
語中有“兩態(tài)”的說法,即主動語態(tài)和被動語態(tài),本單 元中反復(fù)出現(xiàn)的 should be allowed 就是一個含有情態(tài)動詞( should)的被動語態(tài)。 先看幾個基本概念 主語是動作的發(fā)出者為主動語態(tài) 主語是動作的接受者為被動語態(tài) 只有及物動詞才有被動語態(tài)。 2. 被動語態(tài)的構(gòu)成 ( 1)請大 家看圖 The office is cleaned every day . The office was cleaned yesterday. Compare active and passive: 動作的接受者 the office 成了句子的主語,就應(yīng)該用被動語態(tài)。從上面的例句我們可以總結(jié): 一般現(xiàn)在時的被動語態(tài)為:主+ am / is / are ( not)+過去分詞 一般過去時的被動語態(tài)為:主+ was / were +過去分詞 如: Butter is made from milk. This house was built 100 years ago. 以前我們學過的 was / were born 生于,就是一個被動語態(tài) born 是個過去分詞( bear) - When were you born ? - I was born in 1989. 如果要特別強調(diào)動作或行為的執(zhí)行者,句子后面需接 by ~ ,譯為“被 (由)?” 如: We were woken up by a loud noise . 我們被嘈雜的聲音吵醒。 ( 2)請看圖 從上面例子,我們可以看出,現(xiàn)在進行時被動語態(tài)的構(gòu)成為 主語+ is / am / are + being +過去分詞 再如: My car is being repaired now. Some new houses are being built near the park. 公園附近在建一些房子。 ( 3)請看圖 BEFORE NOW 從上面例子,我們可以看出現(xiàn)在完成時被動語態(tài)的構(gòu)成為 主語+ have / has + been +過去分詞 如: My key has been stolen. My keys have been stolen. I am not going to the party , I haven’ t been invited. 含有情態(tài)動詞的被動語態(tài) 情態(tài)動詞+ be+過去分詞 A note had better be left to him. Teenagers should be allowed to wear their own clothes 這里我們列舉了幾個主要時態(tài),那么其它時態(tài)呢? 一般將來時 主語+ will + be +過去分詞 過去將來時 主語+ would / should + be +過去分詞 過去進行時 主語+ was / were + being +過去分詞 過去完成時 主語+ had + been +過去分詞 被動語態(tài)的時態(tài)是由 be的時態(tài)決定的, be 是什么時態(tài),全句就 是什么時態(tài), be 動詞后面的過去分詞不 變。 歸納: 肯定句:主語+ be + 過去分詞+( by ~) 否定句:主語+ be not +過去分詞+( by ~) 一般疑問句: Be +主語+ 過去分詞+( by ~) ? 特殊疑問句:疑問詞+ be+主語+過去分詞+( by ~) 3. 被動語態(tài)的用法: ( 1)不知道或沒有必要說明動作的執(zhí)行者是誰,不用 by+動作執(zhí)行者短語 Such books are written for children. 這 些書是為兒童寫的。 I haven’ t been told about it . 沒有人告訴我這件事 ( 2)強調(diào)動作的承受者,這時應(yīng)用 by 短語。 The cup was broken by David. (