定語從句中as和which

as和which都可以引導非限制性定語從句，先行詞為整個主句或主句中的一部分內容，先行詞在定語從句中作主語、賓語或表語，as與which均不可省略，有時兩者可以互換。下面小編為大家分享定語從句中as和which，歡迎大家參考借鑑。

只用as而不用which：

一、當定語從句置於主句前面時：

例：As you see, the Chinese people are hard-working. (定語從句在句首)

你知道，中國人民是勤勞的。

注意下面句子的多種表達方法：

眾所周知，月球每月繞地球轉一圈。

is known to everybody, the moon travels round the earth once every month.

2. The moon travels round the earth once every month, as/which is known to everybody.

3. It is known to everybody that the moon travels round the earth once every month.

is known to everybody is that the earth travels round the earth once every month.

(後兩句屬名詞性從句範疇)

二、先行詞做主語且定語從句為被動語態時：

此時，從句謂語通常為： be known, be said, be reported， be announced, be mentioned等。如果從句是主動語態，一般用which作主語。

例1：She has been absent again, as is expected.

她又缺席了，這在預料之中。

例2：Tom has made rapid progress, which makes me very happy.

湯姆進步很快，這使我很高興。

另外，as常用在下列習慣用語中：as (it) seems likely, as (it) often happens, as (it) was printed out, as (it) was said earlier, as I remember (it), as I understand (it), as (it) appears, as it often the case, as anybody can see, as we have expected.

例1：Jack has won the first prize, as it often happens.

像往常一樣，傑克得了一等獎。

例2：She has read widely in Romantic Literature, as it appears from her essay ·

她廣泛涉獵了浪漫主義文學，這從她的文章中可以看出來。

只用which而不用as

一、關係代詞代替前面主句中的賓語從句或定語從句的謂語動詞後有複合賓語時：

例：I don't think that he will come to see me, which makes me sad.

我認為他不會來看我了，這使我傷心。

二、which一般用作實義動詞的'主語，這時它所引導的從句與主句之間存在着邏輯上的因果關係時：

例：Tom was late for school again and again, which made his teacher very angry.

湯姆一次又一次上學遲到，這使得他的老師很生氣。

三、當非限制性定語從句是否定句時：

例：He pretended not to know me, which I didn't understand.

他假裝不認識我，我真不明白。

四、非限制性定語從句中的be動詞不能省略時，用which反之用as.

例1：Jane told me she won the match, which was a lie.

簡告訴我她贏了這場比賽，這是謊話。(was不可省略)

例2：As (was) planned, we met at the airport.

按照計劃，我們在機場相見了。(was可省略)