1、Section Grammar语法指南1234非限制性定语从句 非限制性定语从句是对先行词的附加说明,去掉了也不会影响主句的意思,它与主句通常用逗号隔开。The house,which they bought last month,is very nice.这幢房子很漂亮,是他们上个月买的。语法指南12341.非限制性定语从句和限制性定语从句比较:非限制性定语从句 限制性定语从句 形式上 是对先行词的补充说明,删除后主句意思仍完整 是先行词不可缺少的定语,不能删除 译法上 常译成主句的并列句 译成先行词的定语“的”关系词 which,as,whose,whom,who,when,where w
2、hich,that,who,whose,whom,as,when,why,where 语法指南1234Do you still remember the chicken farm which we visited three months ago?(限制性定语从句)你还记得我们三个月前参观过的养鸡场吗?Recently I bought an ancient Chinese vase,the price of which was very reasonable.(非限制性定语从句)最近我买了一个中国古代的花瓶,它的价格非常合理。语法指南12342.非限制性定语从句中关系代词和关系副词的用法:(
3、1)关系代词和关系副词在任何情况下都不能省。(2)who(主语),whom(宾语),which(主语、宾语)不能用that替代,也不能互换。(3)“介词+which/whom+从句”结构中,介词不能移到从句后边。(4)when,where 可用于引导非限制性定语从句。(5)“from+where”引导的定语从句 His head soon appeared out of one of the second storeywindows,from where he could see what was happening on the street.不一会儿,他从二楼的一扇窗户里探出头来,从那儿他
4、能看到街上所发生的事情。语法指南1234(6)“介词+when”引导的定语从句 此时when所代表的常常是前面的句子所提供的时间背景。That was in 1978,since when things have been better.那是在1978年,从那时起情况就好转了。语法指南12343.关系代词 as,which 引导非限制性定语从句的区别:(1)as 引导的非限制性定语从句既可放在主句前,又可放在主句后,有时还可插入主句中;而which 引导的非限制性定语从句只能置于主句之后。相同的是两者都可替代主句的整个内容,而不是主句中的某一个词。The weather turned out
5、to be very good,which was more than we could expect.结果天气非常好,这超出了我们的预料。(2)当非限制性定语从句放在主句前面时,只能用as。As is known to everybody,the moon travels round the earth.=The moon travels round the earth,as/which is known to everybody.众所周知,月亮围着地球转。语法指南12344.当定语从句放在主句后面时,也并不是 as 就永远等于 which。(1)当定语从句是否定句或表示否定意义时只能用 w
6、hich。He came here very late,which was unexpected(not expected).他来这儿时已经很晚了,这是我们没有料到的。(2)当as在从句中做主语时,后面常接动词的被动语态,如be known,be said,be reported,be announced等。如果从句中行为动词是主动语态,一般用which做主语。She has been absent again,as is expected.她又缺席了,这在预料之中。Tom has made rapid progress,which makes me very happy.汤姆进步很快,这使我很高兴。语法指南1234(3)as 多用于下列习惯用语中:as anybody can see 正如人人都能看到的那样;as is well known=as is known to all 众所周知;as we had expected 正如我们所预料的那样;as often happens 正如经常发生的那样;as has been said before 如前所述;as is mentioned above 正如上面提到的。
