Section ⅡGrammar时间、条件和让步状语从句时间、条件和让步状语从句在高考中约占3分，考查形式主要有单选、完型填空、语篇填空和改错，主要考察这三种从句中的引导词、谓语动词。
幻灯片3一、时间状语从句1．no sooner...than与hardly...when都表示主句与从句的动作相继发生，意为“一……就……，刚刚……就”，主句动词用过去完成时。
如no sooner，hardly位于句首时，主句用倒装形式。
He had hardly gone to bed when the doorbell rang.＝Hardly had he gone to bed when the doorbell rang.他刚睡下门铃就响了。
No sooner had he got off the train than his daughter ran towards him.他刚下火车，他女儿就向他跑了过来。
幻灯片42．as soon as，the moment，immediately引导的从句表示从句动作一发生，主句动作随即发生，常译为“一……就”。
名词词组the second，the minute，the moment，every time，any time，next time，the first/last time，the day/week/month等亦可作连词，引导时间状语从句。
They told me about it as soon as/immediately/the moment they got the message.他们一听到口信就把消息告诉了我。
Every time he walked by the lake，he thought of his childhood life.每当他走过那个湖时，就会想起童年的生活。
注意：immediately可用做连词也可用做副词。
幻灯片53．till和until词义是“直到……，一直……为止”，表示一个动作持续到某一时刻或某一动作发生为止，在句首只能用until。
在肯定句中，主句中要用延续性动词；在否定句中，可以用非延续性动词。
She stood there till/until he had passed out of sight.她站在那里看着，直到望不见他的身影。
Until they had finished the work，they did not go home.＝Not until they had finished the work did they go home.直到工作完成了他们才回家。
幻灯片6注意：(1)在not...until结构中not until位于句首时主句部分倒装。
在强调句中，强调until 引导时间状语时，常把not提前，构成It isn’t/wasn’t until...that...。
(2)not...until和not...before意思相同，表示“直到……才，在……以前不”。
幻灯片74．before和since(1)若表达“还未……就……”“不到……就……”“……才……”“趁，还没来得及”时，需用连词before。
He had put the broken vase away before his mother came back.他趁妈妈还没回来就把打碎的花瓶收拾好了。
(2)It will be＋时间段＋before sb.do(does)“多久之后才……”。
It will be 3 days before our manager signs the agreement.要过3天后经理才签那份协议。
幻灯片8(3)since从句的谓语动词一般是非延续性动词，主句的谓语动词是延续性的或者是表示反复发生的动作。
since从句的时态通常是一般过去时，主句中的时态则通常是现在完成时或现在完成进行时。
He has written to me frequently since I got sick.自从我病了以后，他经常给我写信。
幻灯片9(4)在It is＋时间段＋since从句句型中，时间的计算一律从since从句的动作完成或状态结束时算起。
It is half a year since she was in our class.她离开我们班有半年了。
It is three years since he smoked.他戒烟有三年了。
二、条件状语从句1．if和unless(1)if意为“如果”，而unless意为“除非，如果不”。
if...not与unless通常可互换，但if可引导非真实条件句(用虚拟语气)，unless一般不表示非真实条件。
幻灯片10(2)if引导的从句表示好的条件时，可用providing that，provided that，on condition that 等替换；表示不好的条件时，可用so(as)long as替换。
If I were you，I would go to university for further education.我要是你，我会上大学接受更进一步的教育。
They have a meeting every Monday，unless there is nothing to discuss.他们每周一开一次会，除非没有事情可商谈。
幻灯片112．supposing (假如)，suppose (that)(假如)，as (so) long as (只要)，on condition that (在……条件下)，等引导从句，表示“如果，只要，在……条件下”等意义。
in case引导从句，表示“万一……”。
Supposing you are wrong，what will you do?假定你是错的，你怎么办？You can go out，as long as you promise to be back before 11 o’clock.只要你答应十一点钟前回来，你就可以出去。
幻灯片123．only if引导从句用陈述语气，意为“只要……”；if only引导从句用虚拟语气，意为“但愿……，要是……就好了”。
Only if we persist in carrying out the opendoor policy，we will achieve greater success.只要我们坚持实行开放政策，我们就会取得更大的成就。
If only I had known it ，I wouldn ’t have troubled him.要是我早知道那件事，我就不会麻烦他了。
幻灯片134．祈使句＋and/or ＋句子，祈使句表示条件。
Give him an inch and he will take a mile.得寸进尺。
三、让步状语从句1．though ，although ，even if ，even though都有“虽然，即使，尽管”的意思，even if ，even though 语气较强，though 和although 语气较弱。
though 不如although 正式；though 可用于假设，although 用于陈述“事实”。
I had a good time although/though/even if/even though I didn ’t know anybody at the party.尽管在聚会上我谁也不认识，但我还是玩得很高兴。
幻灯片14注意：(1)though ，although 等不与but 连用，但可在主句前加yet ，still 。
(2)though 从句中形容词、名词等为表语时，为加强语气可置于though 前。
2．while 也可引导让步从句，突出对比主句和从句所表示的两种情况。
While he is young ，he is experienced.他虽然年轻，却有经验。
幻灯片153．whether...or (not)可引导让步状语从句，提供两个对比的情况，意为“不管……”。
Whether it rains or not ，I shall go out tomorrow.不管下不下雨，明天我要出去。
4．whatever ，whenever ，wherever ，whoever ，whichever ，however 也可以引导让步状语从句，相当于no matter what (when ，where ，who ，which ，how)，意思为：无论什么，无论何时，无论何处，无论是谁，无论哪一个，无论如何。
however 引导让步状语从句时与它所修饰的词在从句的句首。
幻灯片16Whatever happens ，we shall never lose heart.(＝No matter what happens ，we shall never lose heart.)无论发生什么，我们都不会失去信心。
5．as 引导的让步状语从句必须倒装，结构如下：⎭⎪⎪⎪⎬⎪⎪⎪⎫形容词副词动词分词名词＋as ＋主语＋谓语 幻灯片17 动词或现在分词放在句首，谓语要加助动词do ，does ，did 或will 等；作表语的单数可数名词置于句首时，前不加冠词。
Patient as he was，he was unwilling to wait three hours.他虽有耐心，但也不愿等三个小时。
Hard as she tried，she failed to pass the exam.尽管她努力了，但还是没有通过考试。
Fail as he did，he would never give up.尽管失败了，他也决不会放弃。
幻灯片18幻灯片19Ⅰ.句型转换1．No matter when I see him，he is busy with his research work.→________I see him，he is busy with his research work.答案：Whenever2．Until you told me about it，I had no idea of it.→Not until you told me about it________I________an idea of it.答案：did；have幻灯片203．We had hardly walked into the hall when the lecture started.→Hardly ________we walked into the hall________the lecture started.答案：had；when4．We learn English hard because it is being widely used at present.→It is________English is being widely used at present________we learn it hard.答案：because；that幻灯片215．He left here for three years.→It is three years________he lived here.答案：since幻灯片22Ⅱ.单项填空1．Only if________many different questions ________ acquire all the information you need to know.A．you ask；will you B．do you ask；will youC．do you ask；you will D．you will ask；do you解析：only＋if从句置于句首，从句不倒装，主句应倒装，在条件状语从句中，从句常用现在时表将来，主句常用将来时，故选A。