王萍
while, when與as這三者都可引導時間狀語從句,意為“當……的時候”,很多學生在做題時經(jīng)常弄混這三者的用法,本文結(jié)合實例講解了這三者之間的用法區(qū)別,以期幫助學生在做題時能夠做到心中有數(shù),提高答題的正確率。
一、如果主句和從句中動詞的動作為兩個同時正在進行的持續(xù)性動作時;或者表示“而”的意思,進行對比時,一般用while。
例1:Don’t eat while you are playing.
解析:eat和play都是持續(xù)性動詞,二者同時發(fā)生。
例2:Hu Qiong’s father likes to go out for sightseeing, while Hu Qiong’s brother likes to sleep in his room.
解析:主句和從句的意思有表示對比的意思,句中的while意為“而”。
二、表示“一邊……一邊”或者“隨著”的意思時,引導詞用as。
例3:Zhang Feng drank as he walked.
解析:根據(jù)句意“張鋒一邊走一邊喝?!笨芍龑г~應用as。
例4:Zhang’s children grow taller and taller as time fly.
解析:主從句中的兩個動詞的動作處于發(fā)展變化的情況中,相當于漢語中的“隨著”。
三、如果表示“每當……時”,且暗示某種規(guī)律性時;或者要表示“正在這(此)時”時;如果從句中動詞的動作和主句中動詞的動作是一先一后發(fā)生的時,應用when。
例5:Li Feng and his nephew remained silent when Li Feng’s father criticized them.
解析:句意中含有“每當……時”,引導詞應用when。
例6:Shi Changfeng and his sister were about to go out to work when their friend came in.
解析:句意中含有“正在這(此)時”的意思,引導詞應用when。
例7:Tom’s friend will go his room when Tom comes back.
解析:從句中的動作先發(fā)生,主句中的動作后發(fā)生,故引導詞用when。
四、如果從句中的動詞的動作具有持續(xù)性時,三者均可用。
例8:Cruise became irritable while (when, as)was waiting for his friend at the mall.
解析:從句中的waiting的動作是持續(xù)性的,故三者可同時使用,也就是三者可互換。
注意:當as用于“主短從長”的句子中,意為“在……期間”時,從句中的謂語動詞只能是含有動作與發(fā)展意味的動詞,不能是不能用于進行時態(tài)的動詞,下句中的while不可用as替換。While she is here, can she bring back some specialties?
五、如果從句中動詞的動作是短暫性的,不可用while,可用when或者as。
例9:His uncle had gone out when (as)Jack arrived.
解析:從句中的動詞arrived是短暫性動詞,沒有持續(xù)性,引導詞只可用when或者as。
六、when與as的后面均可以直接加一個名詞構(gòu)成省略句,但是while不可這樣用。
例10:When (As)a girl, her parents were exiled to the western regions, so she often lived a life of insufficient food.(正確)
例11:While a boy, he likes his parents to accompany him at home, but doesn’t like his parents to go out to work.(錯誤)
七、when與while的后面均可以加介詞短語、形容詞、現(xiàn)在分詞等構(gòu)成省略句,但是as不可這樣用。
例12:When (While)watching TV, Sonia’s grandparents kept laughing.(正確)
例13:While (When)in trouble, they remembered the trick their master had given them.(正確)
例14:As reading, her brother called her out to play.(錯誤)
when, while與as在引導從句時,意思和用法相同或相似,學生在做語法填空題或者完形填空題時,如果沒有詳細掌握這三個詞的具體用法,就容易寫錯答案。因此,教師有必要引導學生熟練掌握這三者的用法區(qū)別,以幫助學生提高做題的正確率。