as-when和while的区别PPT课件

1、2021/6/71When，as和while的区别 when/as是是at or during the time that, 既指时间点，既指时间点，也可指一段时间；也可指一段时间； while是是during the time that，只指一段时间。，只指一段时间。 when/as引导的时间状语从句中的动词可以是引导的时间状语从句中的动词可以是终止性终止性动词动词，也可以是，也可以是延续性动词延续性动词， 而而while从句中的动词必须是从句中的动词必须是延续性动词延续性动词。 Sorry, I was out when(as) you called me.He can write onl

2、y when(as/while) the baby is asleep2021/6/72 when 说明从句的动作和主句的动作可以是同时，说明从句的动作和主句的动作可以是同时，也可以是先后发生；也可以是先后发生； as,while 则是同时发生。则是同时发生。 When /While /As she was making a phone call，I was writing a letter.Strike the iron while it is hot. Tom was disappointed that most of the guests had left when he arrived

3、 in the party.2021/6/73when和和while 还可作连词。还可作连词。when表示表示“在那时在那时(突然突然)”常用句型常用句型be doing when be about to do when I was eating with my wife and children when we heard a loud noiseWhile可表示可表示“而，却而，却”，表对比。，表对比。He likes her while she likes him.as常表示常表示“随着随着”；“一边一边，一边，一边”As autumn approaches, it is getting

4、 colder.The little girls sang as they went.2021/6/745. as 还可以表示原因（还可以表示原因（because,for）I didnt visit U as I know you were not at home6.还可以用于倒装结构中，表示尽管还可以用于倒装结构中，表示尽管形、副词形、副词+as+主主+谓，主句谓，主句名词名词(前不加冠词前不加冠词)+as+主主+谓，主句谓，主句Young as he is, he knows a lot.Child as he is, he knows a lot.2021/6/751.（2007山东）山

5、东）_I really dont like art， I find his work impressive.A. As B. Since C. If D. While2. （2007四川）四川）Id like to study law at university_my cousin prefers geography.A. though B. as C. while D. For3. （2007重庆）重庆） _ ，his idea was accepted by all the people at the meeting.A. Strange as might it sound B. As i

6、t might sound strangeC. As strange it might sound D. Strange as it might soundDCD2021/6/764.（2006广东）广东）Jenny was very sad over the loss of the photos she had shot at Canada， _this was a memory she especially treasured.A. as B. if C. when D. Where5. （2006湖南）湖南）I had just stepped out of the bathroom and was busily drying myself with a towel _I heard the steps.A. while B. when C. since D. after6. （哪个不对）（哪个不对）-Im going to the post office.