四川省古蔺县中学2013-2014学年高中英语学案： 关系代词AS的用法 （外研版必修1） WORD版.doc

1、“As”的用法Teaching Aims and Demands1. Get the students to know the relative pron “as”2. Learn the difference between “as” and “which” 3. Revise what we have learned in the last six lessons.The important points1. The functions of “as” used in the attributive clause, and the language situations about it.

2、2. The difference between as and whichThe difficult pointsThe difference between as and which, especially when they lead the un-restrictive attributive clause.Teaching Methods Communication way of teaching, discussion and group work.关系代词as的用法1）关系代词as,在从句中作主 语、宾语和表语。2）先行词被such、as so 和the same修饰，如句型as

3、 many（much）as,或者本身就是such the same 时，从句都用as 引导。Such books as you bought are useful.The school is just the same as it was 10 years agoI read as many pages as are required. 比较下列句子当先行词受the same 修饰时，偶尔也用 that引导定语从句，但与as引导的定语从句意思有区别。This is the same pen as I lost.This is the same pen that I lost.This is s

4、uch an interesting book _as_ we all like.This is such an interesting book _that_ we all like it.11 as与which引导的定语从句1) 在非限定定语从句中，which的先行词可以是名词， as不可The meeting, which was held in the park was a success.2） 关系代词as和which都能引导非限制性定语从句代表整个句子内容，as引导的定语从句可位于句首或句末；which引导的定语从句却不能位于句首。如：As we have seen, oceans

5、 cover more than 70% of the earth.As we all know, the earth is round.3）as代表前面主句意思时，有“正如”之意，而which没有此意思，从句中的动词常是expect, know, see, think, want, suppose等。He won the match, as we had expectedAs we all know, his parents were killed in the war.The police were looking for him, as he thought.6） 当从句和主句语义一致时

6、，用as，反之则用which。She has married again, as was expected.She has married again, which was unexpected.7）as在从句中作主语时，后面常接行为动词的被动语态，如be known，be said，be reported等，如从句中行为动词是主动语态，一般要用which作主语。e.g. She has been late again, as was expected.Tom has made great progress, which made us happy.8).as做主语时， 其后必跟系动词，而which 无此限制The meeting was put off, as was what we wanted.He was murdered, as seemed true.9）在意义上，as引导的定语从句和主句的关系一般为一致关系，常译为“正如”，“就像”，而which引导的定语从句和主句的关系是因果关系，或which引导的定语从句是对主句的评论。因此，在意思通顺的情况下，which可代替as，而as许多时候不能代替which。