2016届高考英语基础知识讲解与训练：连词_高考复习指南

2016届高考英语基础知识讲解与训练：连词

　　疑难突破

　　某些用法比较特殊的从属连词用法区别

　　once作副词译曾经，作为连词译一旦，引导条件状语从句相当于if的加强形式。例如：

　　I don't believe he was once a thief. (once是副词)

　　Once Aristotle had made up his mind that heavy objects always fell faster than light objects, he taught it as a truth to his students. (once连词)

　　till, until作为介词式从属连词引导时间状语短语或状语从句用于否定句时，结构为not …until (till)，主句谓语动词延续与非延续皆可，意为直到才。用于肯定句时，只与延续性动词连用，表示到为止。如：They played volleyball until (till) it got dark./ They didn't talk（延续性动词）until (till) the interpreter（译员）came./ He didn't go to bed（非延续性动词）until (till) the his father came back.；until可以放在句首，till则不行，如：Until the last minute of the match we kept on playing./ Not until he finished his work did he go home.（倒装）；till, until只用于时间，以下句子是错误的：We walked till the edge of the forest.（要用as far as或to）。

　　as作从属连词可引导多种状语从句 as引导时间状语从句，意为当时。如：As (he was) a young man, he was a storekeeper and later a postmaster./ He sang as he worked. as引导方式状语从句，意为象一样。如：We must do as the Party teaches us.　 as引导原因状语从句。意为由于，如：As you are tired, you had better have a rest.　 as引导让步状语从句。意为虽然、尽管Child as he is, he can do it well. ( = Although he is a child, he can do it well.) 另外，as做为关系代词还可以引导定语从句，如：I have the same book as you.