定语从句（Ⅲ）——限制性定语从句和非限制性定语从句

(1)、限制性定语从句的主句和从句之间不用逗号隔开,是先行词意义上不可缺少的宾语,如果删去则意思表达不完整;

非限制性定语从句用逗号与主句隔开只是对先行词起补充说明的作用,如果删去,主句仍能表达完整。

例 His father is not a man who speaks ill of others behind their backs.

他父亲不是一个在别人后说坏话的人。(限制性定语从句)

His father , who never speaks ill of others , is popular with his colleagues.

他的父亲在同事中很受欢迎,他他从不说别人的坏话。(非限制性定语从句)

(2)、限制性定语从句可用that引导;非限制性定语从句不可用that。

例 Do you still remember the teacher that taught us maths in high school?

你还记得高中教我们数学的那位老师吗?

例 We walked down the village street . that was built by local peasants. (错误)

We walked downthe village street,which was built by local peasants.(正确)

我们沿着村子的街道走着，这些街道是当地村民修建的。

(3)、限制性定语从句的先行词是单个的名词或代词;而非限制性定语从句的先行词除单个的名词或代词外,还可以是整个句子。

例 The hotle(先行词) which they are staying at present is very expensive.

他们目前住的酒店非常昂贵。

例 They are coming back to us,which means that they have been refused elsewhere.(先行词是整个句子)

他们要回到我们这儿来，这意味着他们在别处遭到了拒绝。

which引导定语从句的区列

(1)先行词不同:as的先行词是整个句子; which的先行词可以是整个句子,也可以是句中的一部分。

(2)引导定语从句的位置不同:as引导的定语从句位置不受限制; which引导的定语从句只位于主句之后。

(3)意义不同:as意为“正如;正像”;而 which意为“这;这一点”。

例 As is known tous,Ebola is a deadly disease.

众所周知，埃博拉是一种致命的疾病。

例 Green piants produced oxygen,which made land animals appear.

绿色植物释放出氧气来，使陆地动物出现。