DOC《众所周知,which与as都可以引导定语从句,但它们有许多用...》

3、as引导的非限制性定语从句的位置比较灵活,既可位于所修饰的句子之后,也可位于句中或句首;

而由 which引导的非限制性定语从句一般不位于句首.例如: As you will find out,I will never let you down.你将会发现,我绝不会使你失望的.

4、 as引导的定语从句只表示一个众所周知或意料之中的事,但which不受此限制.即as所引导的从句所表达的语意须和主句一致 She has married again,which was unexpected.她又结婚了,真不可思议.这是出乎意料的(此处不可用 as) It is….that….. 是英语学习中常见的一种句型,也是各类考试中出现频率较高的一种句型.很多学生对此句型难以辨别和运用,经常出现一些不必要的错误.那么如何正确运用此句型呢? 为此必须弄清此结构的基本含义.

1 用于强调句型: 此时其具有下列特点. 1) 去掉it, is, that三个单词后句子意义仍然完整;

It is what you said that made me excited. →What you said made me excited. It is what you do rather than what you say that matters. →What you do rather than what you say matters. 2) is只有时态变化而无单,复数变化;

It was Li ping and Zhang ling that told me the news. It was at

5 o'

clock that he finished his homework. It is the cold weather that stops me from attending the meeting. 3) 在强调人时还可以用 who(主语)和whom(宾语);

It is his father who/ that manages the company well. It was the teacher whom/ that I missed greatly. It is the teachers and my parents who/that educated me successfully. 4) 强调地点,时间,原因,方式等不能用where, when, why, how. It was not in the little room that the girl was born. Is it in

2008 that the 29th Olympic Games will be held ? It was because of the rain that he was late for class. I don'

t know it'

s what that made you so sorry.

2 用于定语从句: 1) that 引导定语从句,在从句中充当主语或宾语,此时that可以用 which替代;

It is the dictionary that/ which my brother bought yesterday. It is the book that/ which cost more than

50 yuan. It is an important story which /that we must remember. 2)It is (high) time that….: 是作….的时候. 此句型必须用虚拟语气(一般过去时). It is high time that you went home. It is time that you answered my questions. It is time that you finished your homework now. 3) It is the 1st, 2nd, 3rd,…..time that…..: 此句型必须用完成时态 It is the third time that I have told you the news. It is the second time that I have been here. It was the first time that he had seen the film. It was the fourth time that he had made the same mistake.

3 用于主语从句: 1) It is + n. / adj + that clause. It is necessary that you should hand it in on time. It is a good habit that you help others in trouble. It is a rule that students should go to school on time. 2) It is + -Ved + that clause… It is advised that he should not go to that dangerous place. It is demanded that every student should have a dictionary. It is said that he was once a popular singer.

4 注意其与 It is…. when… 的区别: 在 It is…. when… 中,when引导的是时间状语,而在 It is….that….. 中,that引导的是强调句型,主语从句或定语从句. It is

5 o'

clock when he came back..:他回来时是五点;

It is at

5 o'

clock that he came back.: 他是在五点回来的. Exercise:

1 It was between

1830 and

1835 _____ the modern newspaper was born. A how B that C which D when