1、As、but和than通常都是以介词、连词等身份被大家所熟知,而它们居然可以摇身一变成为关系代词,在定语从句中做主语和宾语。 As As最基本的用法是做连词“与一样”表示同级的比较,介词“作为”。下面是它特殊的用法,例句: 1. He does not possess such qualifications as are necessary to be an actor. 他并不具备一名演员应有的资格。 2. She bought the same skirt as I had bought last week so I need to talk to her about it so we d
2、ont wear them the same at the same time. 她买的那条裙子和我上周买的一模一样,我要和她商量一下,免得“撞衫”。上面两个例句中定语从句都使用了as作为关系代词,我们可以发现例句1中含有 “suchas”,例句2中含有“the sameas”,由此可见,我们到底要不要使用as来做关系代词,可以根据句中是否出现了与as搭配的短语进行判断。 3. The murderer who had killed several people on the campus was finally arrested by the police, as was expected.
3、 如我们所愿,那个在校园杀害数人的杀人犯终于被警方逮捕。该句中并未出现与as搭配的短语,此处的用法是as做关系代词指代前面整个句子,在定语从句中做 主语。 But 大家熟悉的but基本都是以转折连词的身份出现,但是它还兼职在做定语从句中的关系代词。例句: There is no man but errs. 没有任何人能够不犯错误。句中的先行词是man,but自然就充当了关系代词的角色,但我们从句意中可以发现,but带有一层否定的意思,相当于“who not”。那么我们可以把例句转换为: There is no man who does not err. 但要注意,只有在but 前有先行词的时候
4、才有此用法!请比较下面这个例句: He did nothing after graduation but spend his parents money. 他毕业之后无所事事,就知道花爸妈的钱。该句中but是介词的用法,有转折的意义。 Than 即可以做连词也可以做介词的than都是比较的含义,它居然也可以用在定语从句中。例句: 1. Parents had better not give kids more money than is needed. 父母最好别给孩子们太多的钱,够用就可以了。 2. Dont order more food than can be finished. 别点太
5、多吃的,会吃不完的。此处Than以主语的形式出现在定语从句中,其实省略了what,than也就等于than what。例句也可以写作:Parents had better not give kids more money than what is needed 例句2则可以转换为:Dont order more food than what can be finished 不管是做介词、连词也好,在定语从句里做关系代词也罢,than都表示了一个比较的关系,从上述两个例句来看,句中都出现了比较级的形式。一、but可被看作关系代词,引导定语从句,在句中作主语,在意义上相当于 who not或tha
6、t not,即用在否定词或具有否定意义的词后,构成双重否定。 如:There is no mother but loves her children没有不爱自己孩子的母亲。 There was no one present but knew the story already在场的人都知道这个故事。 二、than作关系代词时,一般用在形式为比较级的复合句中,其结构为形容词比较级(more)than从句,than在从句中作主语,相当于 that,代表它前面的先行词。(这时,它兼有连词和代词的性质,也有学者认为这种用法的than是连词,后面省略了主语what。) 如:The indoor swim
7、ming pool seems to be a great deal more luxious than is necessary室内游泳池过于豪华。 He got more money than was wanted他得到了更多的钱。定语从句中的两个特殊关系代词 定语从句是中学阶段一个非常重要的语法项目,在各类考试中都能看到它的身影。它的基本用法,想必读者朋友们已经掌握了吧!现由笔者为大家再介绍两个定语从句中的关系代词but和than,以飨读者。一 butbut在定语从句中作关系代词,通常情况下只能充当从句的主语。此时,but为否定含义,相当于thatnot或whonot,并且此时的主句多为
8、否定句或疑问句。例如:Not a man but had tears in his eyes.没有一个人眼睛里不含着眼泪。There was no one but knows that.没有人不知道那件事。There is no rule but has exception.凡规则都有例外。There is not one of us but wishes to help you/peace.我们之中没有一个人不愿意帮助你/希望和平。There is no tree but bears some fruit.无树不结果。(谚语)二 thanthan在定语从句中作关系代词,在从句中可以充当主语、
9、宾语、表语,但仍以充当主语为多。在定语从句中,它与关系 代词that所起的语法作用是差不多的,只是在翻译或解释时,要比that多一层比较的意味。另外,由than含有比较意味可知,该类定语从句的先行词前 通常要有形容词的比较级形式。例如:You make more money than is intended to make.(主语)你挣得的钱比预计的要多。There was more casualties than was reported.伤亡人数比报道的要多。During the winter holidays, I made much more money than Li Ming did.(宾语)在寒假期间,我挣的钱比李明多得多。He got to know a famous writer who knew much more knowledge than his own (knowledge was).他认识了一位比自己有更多知识的优秀作家。 (注:专业文档是经验性极强的领域,无法思考和涵盖全面,素材和资料部分来自网络,供参考。可复制、编制,期待你的好评与关注)