专题二十一 连词
重难点分析
连词是一种虚词，它不能独立担任句子成分而只起连接词与词、短语与短语以及句与句的作用。连词可以分为两类：并列连词和从属连词(引导各种从句的连词)。
一、连词的用法归纳 并列连转折关系 并列关系 and, when(就在这时=and just at this/that time), not only…but also, neither…nor, both…and but, while (而、尽管), yet, not…but or, either…or, otherwise, or else (否则、要不然) for, so who/that(主语), whom/that(宾语), whose(定语) which/that(主语或宾语), whose(定语) 注意：非限制性定语从句中不用that 词 选择关系 因果关系 定语从关系 代词 关系先行词是人 先行词是事或物 先行词是时间: when (状语)；先行词是地点: where (状语)；先行词是reason: why (状语) 句 副词 名词性从句 连接代词 连接副词 状语从地点状语 条件状语 原因状语 结果状语 时间状语 连词that 没有词义，不作句子成分，引导宾语从句时可省略；即句子的结构与意义完整时，填that 连词if/whether 意为“是否”，不作句子成分，引导宾语从句时，一般可互换，但在介词后或discuss后引导宾语从句时，只能用whether。但引导其他名词性从句时，一般也只能用whether 有意义，作句子成分：who, whom, whose, which, what 有词义，作句子成分：when, where, why, how when, while, as, before, after, once, till, until, since, every time, the moment, hardly…when, no sooner…than, as soon as where, wherever (无论什么地方、不管哪里) if, unless (除非), as/so long as (只要), on condition that (如果), in case (如果、万一) because, since, as, now that (=since 既然、由于) so that (结果), so…that, such…that (如此……以至于……) so that (为了、以便), in order that, in case (以防万一), for fear that (以防、以免) although, though, as (状语或表语要提到as前，作表语的单数可数名词提前时，不用句 目的状语 让步状语 a), even if, even though (即使), whether…or…(不管……还是), whoever (=no matter who), whatever (=no matter what), whenever (=no matter when), whichever (=no matter which) 比较状语 方式状语 than, as…as, not as…as, not so…as, the same…as, such…as, the more…the more as (像、依照), as if, as though (好像、仿佛) 注意：定语从句、状语从句、名词性从句的详细讲解可见专题13、14、15。
二、连词的使用难点与易错点归纳
因为连词的种类非常多，有并列连词（连接并列句），有从属连词（引导复合句），而从属连词引导的从句又可分为三类：定语从句、状语从句和名词性从句。尤其应注意的是有些连词可引导不止一种从句，具有多重功能，这往往是学习的难点，也是易混点。
难点回顾：
1. as可引导多种从句，如时间状语从句、原因状语从句、让步状语从句、方式状语从句、比较状语从句以及定语从句。
[误] Which you can see, he is always ready to help others. [正] As you can see, he is always ready to help others. 解析：as引导非限制性定语从句，当“正像/正如”讲。 [误] Do like I told you. [正] Do as I told you. 解析：like是介词；as是连词，在这里作“按照”讲，引导方式状语从句。 [误] He was reading then he was walking. [正] He was reading as he was walking.
解析：as强调两个动作同时进行，作“一边……一边……”讲。 [误] As he is young, he knows a lot. [正] Young as he is, he knows a lot.
解析：as引导的让步状语从句应用倒装语序，应把表语提前。 2. that可引导多种从句，如定语从句、名词性从句、状语从句等。 [误] You don’t like him is none of my business. [正] That you don’t like him is none of my business.
解析：that引导主语从句，本身无实际意义，但不能省略。
[误] The thief handed everything which he had stolen to the police. [正] The thief handed everything that he had stolen to the police. 解析：everything是不定代词，因此后面的定语从句只能由that引导。 [误] I am happy as you passed the exam. [正] I am happy that you passed the exam. 解析：that在形容词后面引导宾语从句，不能用as。
3. where可引导多种从句，如定语从句、状语从句以及名词性从句。 [误] Go to find your watch. It’s there where you left it. [正] Go to find your watch. It’s where you left it.
解析：where引导表语从句，相当于at the place where。 [误] The place where there is water, there is life. [正] Where there is water, there is life.
解析：where引导地点状语从句，可以放在主句的前面，也可以放在主句的后面。 [误] I can’t remember in which place I met him. [正] I can’t remember where I met him. 解析：where引导宾语从句，不能用in which。 4. what可引导感叹句、特殊疑问句、名词性从句等。 [误] How an interesting story he told us! [正] What an interesting story he told us!
解析：What an interesting story！= How interesting a story！ [误] I can’t remember the thing what he told me. [正] I can’t remember what he told me. 解析：what引导宾语从句，相当于the thing that。
5. no matter + what/who...与whatever/whoever...的区别：前者只能引导让步状语从句，而后者既可引导让步状语从句，也可引导名词性从句。
[误] I will make friends with no matter who shares my interest. [正] I will make friends with whoever shares my interest. 解析：引导名词性从句时只能用whoever。 [误] You must hand in no matter what you’ve found. [正] You must hand in whatever you’ve found.