1 语法复习十八:连 词 连词分为并列连词和从属连词两大类。并列连词是连接主语与主语,谓语与谓语,句子与句子,分词与分词的词,它要求前后两部分有相同的形式和语法作用;而从属连词一般连接主句与从句,从句形式有名词性从句,定语从句和状语从句等。 (一)并列连词: 并列连词可用来连接词与词,词组与词组,分句与分句。常用的并列连词有:and(和),as well as(既„又),both … and(不但„而且),not only … but also(不但„而且),not … but(不是„而是),neither … nor(既不„也不),either … or(不是„就是),or(或者),but (但是),yet(然而),for(因为),so(所以),while(而),when(这时)等。如:Both my brother and my sister are teachers./ His room is bright but mine is gloomy(暗沉沉的)./ He can not only repair radios but also fix them./ It is a glorious(光荣的)yet difficult task./ Strike while iron is hot. (二)从属连词 从属连词是指在复合句中引导从句的连结词。常见的从属连词有: 引导时间状语从句的:after, before, when, as, while, since, until, till, as soon as 引导原因状语从句的:because, since, as 引导让步状语从句的:although, though, no matter(无论), even if (though) 引导条件状语从句的:if, unless, once, so (as) long as 引导结果状语从句的:so … that …, such … that … 引导目的状语从句的:so that …, in order that … 引导比较状语从句的:as … as …, not so (as) … as …, … than … 引导方式状语从句的:as if … 引导主语,宾语或表语从句的连词主要有:that, whether, if 三个。其中 that 和 whether间或还可以引起同位从句和状语从句。 (三)某些用法比较特殊的从属连词用法区别 1、当 w hile, w hen, as 引导时间状语从句时的区别:①while 引导的状语从句中动词必须是持续性。谓语动词多为进行时,或状态动词的一般时。while 的这些用法可用 when 代替,等于 “at the time that”, “during the time that”。例如:Please keep quiet while (when) others are studying;② when 除可指一段时间外,还可用来指一点时间,等于 “at the time”,也...