asif的用法PPT教学课件

1、 一、as if 从句的作用 1.1.as ifas if一般可由一般可由as thoughas though来代替。来代替。可在可在look, seemlook, seem等系动词等系动词后引导后引导表语表语从句从句。He looked as if / though he was ill. It seems as if it is going to rain.第1页/共15页 一、as if 从句的作用 2.2.引导引导方式状语从句。方式状语从句。 She loves the boy as if she were his mother The child talked to us as if

2、 he were a grownup第2页/共15页二、二、as if as if 还可用于还可用于省略句中，省略句中，如果如果as if as if 引导的引导的从句是从句是“主语主语bebe动词动词”结构，可省略结构，可省略主语和系动词主语和系动词，这样这样as if as if 后就后就只剩下名词、不定式、形容词（短只剩下名词、不定式、形容词（短语）、介词短语或分词语）、介词短语或分词。 He acts as if （he was） a fool Tom raised his hands as if （he was going） to say something. She left th

3、e room hurriedly as if （she was）angry（as if+名词）名词）（as if+不定式不定式）（as if+形容词形容词）第3页/共15页 He looked about as if (he was) in search of something. He paused as if (he was) expecting Mary to speak.（as if+介词短语介词短语）（as if+现在分词现在分词）第4页/共15页 EXERCISES:EXERCISES: The man opened his eyes and moved his lips as i

4、f_that he had something to tell the the doctor.（say） (he was going) to say第5页/共15页 三、as if 从句的语气及时态 1 1 as if as if 从句从句用陈述语气用陈述语气的情况。的情况。 当说话者认为句子所述的是当说话者认为句子所述的是真实的或极有真实的或极有可能发生或存在可能发生或存在的事实时。的事实时。It sounds as if it is raining He talks as if he is drunk 第6页/共15页 三、as if 从句的语气及时态 2 2as if as if 从句用

5、从句用虚拟语气虚拟语气的情况。的情况。 当当说话人认为句子所述的是说话人认为句子所述的是不真实的或极少不真实的或极少有可能发生或存在有可能发生或存在的情况时。从句虚拟语的情况时。从句虚拟语气动词时态的形式如下：气动词时态的形式如下：第7页/共15页 三、as if 从句的语气及时态 （1 1）如果从句表示）如果从句表示与现在事实相反与现在事实相反，谓，谓语动词用语动词用一般过去时一般过去时。动词是。动词是bebe时，一时，一般用般用were.were. You look as if you didn t care He talks as if he knew where she was 第8页

6、/共15页 三、as if 从句的语气及时态 EXERCISES:EXERCISES: 1. I cant stand him. He always talks as if he _ everything. (know) 2. When a pencil is partly in a glass of water, it looks as if it _ (be) broken. knewwere第9页/共15页 三、as if 从句的语气及时态 （2 2）从句表示与）从句表示与过去事实相反过去事实相反，谓语，谓语动词用动词用“had“had过去分词过去分词”。 He talked about

7、 Rome as if he had been there before The girl listened as if she had been turned to stone.第10页/共15页 三、as if 从句的语气及时态 EXERCISES:EXERCISES:1. The two strangers talked as if they _ friends for years.(be) 2. He looked as if he _ ill for a long time. 3. He looked happy as if he _ (persuade)her to change

8、her mind. had beenhad beenhad persuaded第11页/共15页 三、as if 从句的语气及时态 （3 3）从句表示与）从句表示与将来事实相反将来事实相反，谓语，谓语动词用动词用“would“wouldcouldcouldmightmight动词原动词原形形”。 He opened his mouth as if he would say something It looks as if it might snow第12页/共15页 三、as if 从句的语气及时态 (4)as if (4)as if 后面可以接陈述语气和虚后面可以接陈述语气和虚拟语气，如果句

9、子的情况是拟语气，如果句子的情况是真实的真实的，那么，那么只要只要保持时态一致保持时态一致即可，如果后面接的即可，如果后面接的并并非真实情况非真实情况，则要按照，则要按照虚拟语气规则虚拟语气规则把句把句子形式改变（简单说就是子形式改变（简单说就是时态时态倒退原则倒退原则）。）。 It seems as if it is raining。外面看起来象是下雨了。（陈述） It seems as if it were raining。外面看起来好像下雨一样。（虚拟，其实并没有下雨）第13页/共15页 EXERCISES:EXERCISES:1. He looked happy as if he _ (persuade)her to change her mind.2. I dont know why she is looking at me as if she _(know) me. Ive never seen her before in my life