狀語從句可分為時間、地點、原因、目的、結果、方式、讓步、條件和比較狀語從句,其中有些連詞可引導多種狀語從句,表達不同的意義;也有某一從句可用多個連詞引導,表達相同的意義,這就使得狀語從句成為一大難點,下面就容易引起混淆的引導詞作簡要介紹。
一、while while常表示“當……的時候;然而;盡管”。
如:The students were busy taking notes while they were listening to the lecture. The young mostly enjoy pop music while the old usually prefer classical. While there exists much unemployment in almost all cities, people with special skills are still in great demand.
注意:while 表示“盡管”時,相當于although / though / as,但while / although引導的讓步狀語從句不用倒裝語序,though引導的狀語從句可以倒裝也可以不倒裝,而as引導的狀語從句則必須倒裝。
如:Though the bride is happy / Happy though the bride is, she will feel homesick at the beginning. Happy as the bride is, she will feel homesick at the beginning.
二、until和till until和till都表示“直到”,常可互換,但till一般不用于句首,也不可用于強調句中。
1. until / till從句或短語與肯定的主句連用時,主句的謂語必須是延續性動詞,表示主句的動作一直持續到until / till所表示的時間為止。
如:You may stay here until the rain stops. Mr. Bush remained there till his brother arrived.
2. until / till從句或短語與否定的主句連用時,主句的謂語必須是非延續性動詞,表示“直到……才”,即主句的動作到until / till所表示的時間才開始。
如:David won‘t go to bed until / till his wife returns. Leo didn’t come until he had gone over his lesson.
3. not until ......位于句首時,主句須用倒裝語序。
如:Not until I began to work did I realize how much time I had wasted.
4. not until …… 結構可用于強調句中。如:It was not until she came to see us that we knew her mother was ill in bed.
三、so that so that可以引導目的狀語從句與結果狀語從句。
1. 當表達的含義是“為了、以便”時,為目的狀語從句,此時,從句的謂語部分通常帶有情態動詞;當表達“以至于、因此”時,為結果狀語從句。
如:If you do know,answer in a loud enough voice so that all the class may hear.(目的狀語從句)It rained hard the day before yesterday,so that we had to stay at home.(結果狀語從句)
2. 當從句之前的so that可用in order that代替時,為目的狀語從句;反之,為結果狀語從句。
如:We now study hard so that we may work well in the future. (= We now study hard in order that we may work well in the future.) (目的狀語從句)
(作者單位:河北省衡水市第十四中學)