高三英语when的用法

【知识要点】归纳when的用法
When的用法是近十多年来高考试卷中的 一个高频考点，既考查其在特定语境中的常 规意义, 也考查特殊意义 .
Ⅰ 1. when作从属连词引出状语从句，“当……时” ②He transplanted the little tree to the garden when it was the best time for it. ⑤The car helps to keep families together when it is used for picnics, outings and other shared experiences. ①(2009年重庆卷) Peter was so excited ____ he received an invitation from his friend to visit Chongqing. A. where B. that C. why D. when ②(2008年四川卷) There were some chairs left over _____ everyone had sat down. A. when B. until C. that D. where
注意：从句有时可简化为“when+现在分词/过去分词/形容词/名 词/介词短语”
（ 1 ） 入乡随俗 When in Rome， do as Romans do. . （ 2 ） When （we are ） young， we are full of hope. 年轻时，我们大家总是充满希望。 standing （ 3 ） Don't reach sideways when __________ (stand)on a ladder. 站在梯子上时，不要侧着身子去够东西
⑧It was foolish of you to take a taxi when you could have easily walked there in five minutes.
（ 1 ） She paid when she could have entered free. 本来可以免费入 场，而她却付了款。 might have succeeded （ 2 ） She stopped trying when she ______________________ next time. 她本来下次有可能获得成功，但她却不再尝试了。 （ 3 ） They were gossiping， when theyshould have been working _____________________. 他们本该工作，却在那里说别人的闲话。
他什么时候回来很多取决于天气。 When she’ll be back depends much on the weather.
①(2009安徽卷) A good friend of mine from ____ I was born showed up at my home right before I left for Beijing. A. how B. whom C. when D. which
when 还可以接不定式 when to go sightseeing Have you decided ______________________(何时去观光)？ When have you been here？ How long have you been here？ √ ☆when问的是具体时间，所以不能和完成时连用。 What time does the train leave? 强调具体是几点几分.可以与When混用. When will you graduate?
解析：考查when引导的宾语从句。句中“when I was born”作介词from的宾 语，修饰限定前面的a good friend of mine。句意为：在我动身去北京之前， 儿时的一个好友来到了我家。
②(2006 全国Ⅰ) Please remind me _____ he said he was going, I may be in time to see him off. A．where B. when C. how D. what
B 可以作“既然，考虑到”解，引导原因状语从句，相当于since, now that, as或considering that
I can’t tell you anything when you won’t listen.
既然你不想听，我就什么也不告诉你了。
How could you, when you knew that this might damage it? 既然你知道这样会损害它，你怎么能这样做呢？
Choose the best answer
D 1 We are living in an age ______ many things are done on computer. A. which B. that C. whose D. when B 2 He transplanted the little tree to the garden ___ it was the best time for it. A. where B. when C. that D. until 3 Jas was holidaying with her family in a wildlife park ______ she was bitten on the leg by a lion. A A. when B. while C. since D. once
4. when表示“还没……就……” ”刚……就；一……就” ⑦I had hardly covered more than 30 miles in the snow when I found that the fuel was used up.
常见下列结构： Hardly/scarcely/barely had 主语 done when 主语 did 使用该句型时要注意： ① hardly 后的谓语动词用过去完成时 ,when后谓语动词要用过去时 ②hardly位于句首时, hardly 后的句子要倒装，而when引导的句子 不倒装。 （ 1 ） 我们刚刚入睡，铃声就响了起来 We had hardly fallen asleep when the bell rang. _____________________________________________________ Hardly had we fallen asleep when the bell rang. （ 2 ） He had scarcely arrived when he had to leave again. ______________________________________。 他刚刚到达就又要离开了。
asked ( 4 ) When __________(ask) about the possibility that Justin was taken by aliens.
2. 表示对比，“既然；本（应该、可以）……却（而） ……，” A. when后面的从句谓语动词常用虚拟语气。
Βιβλιοθήκη Baidu
引导让步状语从句，意为“虽然；然而；可是”，相当于although
3. 表示条件，相当于 if ，引导条件状语从句。 但when作“如果；要是”解通常表示对某事是否会发生有把握 ,if 则表示对某事是否会发生没有把握 How can I get a job when I can't even read or write？ 如果我连读和写都不会，我怎么能找到工作呢？ How can you hope for mercy when you show none?
解析：考查when引导的宾语从句。When 在从句中作时间状语，句子意思为 ：“提醒我他什么时候走，我好及时给他送行”。
When 引导疑问句有两种构成： （1）介词Since/Till +when+一般疑问句？（注：此时when作疑 问代词，作介词的宾语。）； （2）when+一般疑问句？（注：when 作疑问副词，在特殊疑问 句中作状语。）。 （2007 陕西卷）-______ when has the country been open to international trade? - 1978, I suppose. A. Since B. In C. From D. After 解析：since 意为“自从”，常与现在完成时连用，表示动作从 某个时候开始，一直延续到现在。此题根据特殊疑问句中的时态 可判断用since，句意为：这个国家从什么时候起进行国际贸易的 ？
4 We were just ___ calling you up ___ you came in. C A.about; when B. on the point of; while C. on the point of; when D. on the point of; as 5 The car helps to keep families together ___ it is used for D picnics, outings and other shared experiences. A. so that B. even though C. unless D. when 6 His parent has been saving like crazy in the past five years for ___ he will go to university. B A. if B. when C. where D. why D 7 I had hardly covered more than 30 miles in the snow _____ I found that the fuel was used up. A. while B. since C. until D. when A 8 It was foolish of you to take a taxi ______ you could have easily walked there in five minutes. A. when B. while C. but D. though
如果你不宽恕别人，你怎么能希望得到别人的宽恕呢？
比较：
Let me know when you need money. (I’m sure you’ll need money)
Let me know if you need money. (perhaps you’ll need money)
Don’t be afraid of asking for help ______ it is needed.(NMET2003 A. unless B. since C. although D. when
When did you come here？ 你什么时候来这里的？ 译：———————————————— when you came here. I don't know__________________________ Ⅱ when引导的特殊疑问句调整成陈述句语序，在主句中不同 的位置做不同类别的名词性从句，通常翻译为在何时或在那时 ⑥His parent has been saving like crazy in the past five years for when he will go to university.
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强调大体上的时间,此处不能用What time.
what time 指具体的时间的，而when 指 大体的时间
Ⅲ when引导定语从句，翻译为在那时 ①We are living in an age when many things are done on computer. (2009江苏卷) Because of the financial crisis, days are gone _____ local 5-star hotels charged 6, 000 yuan for one night. A. if B. when C. which D. since