《大学生英语竞赛_词汇与结构》.ppt

2）连词whether一般引导名词性从句。当引导让步状语从句时，必须用逗号和主句分开，而且其前边可以加no matter。 【例句】You’ll have to do it, (no matter) whether you like it or not. 3）whatever, whenever, whoever, whichever和however引导让步状语从句, 相当于no matter what (when, where, who, which,和how)，意思是：“无论什么，无论何时，无论何处，无论谁，无论哪一个，无论如何”，表示无论在什么条件下进行随意的选择。 【例1】Whatever (No matter what) happens, we shall never lose our heart. 1）as…as, the same as和such…as 用于表示同等程度的比较，否定句用not so(as)…as, not the same…as, not such…as。 【例1】The movie was not so interesting as we had expected. 【例2】She sings too loudly, the same as her teacher does. 2）as和than 连接的比较状语从句常常省去与主句相同的部分，只留下相比的部分。 【例句】Actions speak louder than words. 3）在as和than连接的从句中，常用替代词do或其它助动词或情态动词的某种形式代替与主句相同的谓语部分。【例句】Emily studies as hard as Amy does. 1）as引导的方式状语从句通常位于主句后。(just) as…so…引导的方式状语从句常位于句首，这时as从句带有比喻的含义，意思是 “犹如……”，“就像”，多用于正式文体。 【例1】The child did everything as he was told to. 【例2】Just as the moon goes round the earth, so the earth revolves around the sun. 2）as if, as though 两者的意义和用法相同，引出的状语从句谓语多用虚拟语气，表示与事实相反。有时也用陈述语气，表示所说情况是事实或实现的可能性较大。汉语常译作 “仿佛……似的”，“好像……似的”。 【例句】It looks as if the weather may pick up very soon. * * * * * * * * * * * 2）表示“一……就……”的连词和词组 （1）表示“一……就……”的连词有as soon as, hardly…when, scarcely…when, no sooner…than等。【例】I will write to you as soon as I get home. （2）表示“一……就……”的词组有the instant, the moment, the minute, the second, instantly, directly, immediately等。 【例】I fell in love with the pretty girl the moment I saw her. （3）as soon as引导的从句中的谓语动词常用一般现在时代替一般将来时，或用一般过去时态表示过去将来时。 【例】I would tell him the news as soon as I saw him. （4）hardly…when, scarcely…when, no sooner…than的意义相当于as soon as，引导时间状语从句时，从句谓语动词用一般过去时，主句谓语动词用过去完成时。hardly, scarcely及no sooner位于句首时，主句则要部分倒装。 【例2】Hardly / Scarcely had we got home when it begain to rain. 【例3】No sooner had she entered the house than the telephone rang. 3）since时间状语的用法 （1）since引导的时间状语从句谓语动词用一般过去时，主句用完成时。 【例】Since he left the university, he has been working in an accounting company. （2）since常用于“It is / has been …(一段时间)＋sin