主从复合句中时态的一致主要有以下几种情况.docVIP

主从复合句中时态的一致主要有以下几种情况：一、在以when，after，as soon as等引导的时间状语从句以及以if，unless等引导的条件状语从句中，如果主句是一般将来时，从句则用一般现在时。例如：Ill tell her the good news when she comes back.当她回来的时候，我将把这个好消息告诉她。If it doesnt rain, he will come here on time.如果不下雨，他会按时来这儿的。二、在含有宾语从句的主从复合句中，当主句的谓语动词为过去时态时，从句须用表示过去的某种时态。例如：He asked when they would go to the party.他问他们什么时候将去参加聚会。Miss Green said she had been to Beijing before.格林小姐说她以前曾经去过北京。三、在宾语从句中，当主句的时态为一般现在时、现在进行时、现在完成时等时态时，后面从句时态不受主句限制，可根据情况，选用各种适合的时态。例如：Do you know when well have a football match?你知道我们什么时候举行足球赛吗？You know he has gone to Shanghai.你知道他已去上海了。四、当宾语从句表述的是客观事实、科学真理、现在的习惯动作以及格言等时，其时态不受主句限制，而用一般现在时。例如：The teacher told us that light travels faster than sound.老师告诉我们光速比音速要快。When I was a student, my teacher often told us that time and tide wait for no man.当我还是学生的时候，老师常常告诉我们，岁月不等人。五、在since点时间句型中，主句通常用现在完成时，从句用一般过去时。例如：He has worked at the factory since he came here.自从他来到这儿，他就一直在这家工厂上班。另外，在句型Its+段时间since从句中，since后面的从句要用一般过去时。例如：Its a long time since we met last.自从我们上次见面以来已经有好长时间了。六、在复合句中，如果主、从句表示的动作或状态都发生在过去，而且有先后，则在先的用过去完成时，在后的用一般过去时。例如：When he got there, the train had left.当他到那儿的时候，火车已经开了。He said he had visited the school before.他说他以前参观过那所学校。 一、It引起的几个易混淆的时间句型在学习中，同学生们对It + be + 时间 + 从句这个结构经常混淆不清，下面逐一进行分析。1. It + be + 时间 + since-clause这个句型表示从since 从句谓语动作发生以后到现在或过去所经过的一段时间，意为自从.以来已多久了，主句多用一般现在时，从句用一般过去时，如果表示过去的情况，主句用一般过去时，从句用过去完成时，或主句用过去完成时，从句用一般过去时。例如：It is three years since his father passed away . (从现在算起)It was 10 years since they married . (从过去算起)It had been fifteen years since she left Shanghai . (从过去算起)30 years has passed since we joined the Party . (从现在算起)2. It + be + 时间 + before-clause这个句型中的时间一般为表示一段时间的词语(如：long years , months , weeks , days ,hours , minutes ) ，主句中的谓语动词用肯定式，意为过多长时间才.。主句的谓语动词是否定式时，意为没过多长时间就.。主句的时态可用过去时was或将来时will be；用was 时，before从句的动词用一般过去时；用will be 时，before从句常用一般现在时。 例如：It was not long before she learned those poems by heart . 她没过多久就背会了那些诗歌。It was long before the police arrived .过了很久警察才来。It will be hours before he makes a decision . 要过好几个小时他才会作出决定。It will not be hours before meet again . 要不了几个小时我们还会再见面的。3. It + be + 时间 + when-clause这个句型中, it 指时间，而且表示时间的词语前没有介词(时间一般为具体时间)。主句中的谓语动词和从句中的谓语动词在时态上一般是一致的，主句是will be，when从句用一般现在时代替将来时。例如：It was already 8 oclock when we got home .It was the next morning when we finished our work .It will be midnight when they get there .4. It + be + 时间 + that-clause这个句型是个强调句型。例如：It was two years ago that he made an important invention .(原句是：He made an important invention two years ago . )It was at 5 oclock that he practised playing the violin in the morning .(原句是：He practised playing the violin at 5 oclock in the morning . )比较：It was 5 oclock when he started in the morning .(5 oclock前没有介词，这是个定语从句)5. It + be + time + that-clause这个句型属虚拟语气结构，不管主句中用的是 is 或 was ，that从句都须用动词的过去式或should + 动词原型(但不及用过去式普通)，在time之前有时可加上high或about 以加强语气。例如：It is time(that)we handed in our exercises .(= It is time that we should hand in our exercises .)It is high time (that ) she wrote a letter to her boyfriend .6. It / This / That + the first(second , third .) time + that-clause这个句型表示截止到说话时为止的某人的一种经历，关键是注意time前有序数词，主句是 is 时 ，从句要用现在完成时；如果主句用一般过去时was ，则从句须相应地用过去完成时。例如：This is the first time (that) these Europeans have visited the Great Wall .It was the fifth time (that) I had paid a friendly visit to Africa .二、It代替从句作形式主语的常见句型1. it 代替连词 that 引导的从句作形式主语。1) it + be + 过去分词 + that 从句Its said that Tom has come back from abroad . 据说汤姆已经从国外回来了。It was reported that dozens of children died in the accident . 据报导，数十名儿童在事故中死亡。可用于该句型的过去分词还有：known , thought , told , believed , hoped , announced ,expected , decided , suggested等，该句型常可以转换成含有宾语从句的复合句或者含有不定式作主补的简单句。如：Its said that Tom has come back from abroad . People say that Tom has come back from abroad . He is said to have come back from abroad .2) It + be + 名词词组 + that 从句Its a pity that he cant swim for his age . 真遗憾，就他的年龄来讲，他竟不会游泳。Its a wonder that you could finish such a hard task in such a short time . 真奇怪，你竟能在如此短的时间内完成艰巨的任务。可用于该句型的名词词组还有：an honour , a good thing , a fact , a surprise , good news等。3) It + be /seem + 形容词 + that 从句It is likely that they will beat us tonight .今晚很可能他们会赢我们。It doesnt seem that she will give us a hand .她帮我们的可能性似乎不太大。可用于此句型的开容词还有；wonderful , true , good , right , wrong , (un)important ,useless , surprising , clear , possible , unusual , lucky , certain 等。4) It + seem / appear / happen + that 从句It seems that he enjoys pop songs very much .看来他非常喜欢流行歌曲。It appears that Tom might change his mind .看来汤姆会改变主意。It happened that I went out that day .碰巧我那天外出了。注意，句型4可转换成含不定式的简单句。如上述句子可转换为：He seems to enjoy pop music very much . / Tom appears to change his mind ./ I happened to go out that day.2. it 代替连接代词或连接副词引导的从句作形式主语。1) It is known (not decided , not made clear , found out , discussed , being discussed , being considered , a question , uncertain等) + 连接代词或连接副词引导的从句。It is still a question when we shall have our sports meet . 我们将什么时候举行运动会还是一个问题。It is uncertain whether he can attend this conference or not . 他能否来开会还不能确定。2) It doesnt matter(doesnt matter too much , doesnt make too much difference等) + 连接代词或连接副词引导的从句。如：It doesnt matter whether we go together or separately . 我们一起去还是分开去都可以。It doesnt matter too much to me what you do or where you go . 你做什么或去什么地方，对我都无关紧要。【动脑动手】反意疑问句 1) 陈述部分的主语是I，疑问部分要用 arent I. Im as tall as your sister，arent I?2) 陈述部分的谓语是wish，疑问部分要用may +主语。 I wish to have a word with you, may I?3) 陈述部分用 no, nothing, nobody, never, few, seldom, hardly, rarely, little等否定含义的词时，疑问部分用肯定含义。 The Swede made no answer, did he / she? Some plants never blown (开花), do they ?4) 含有ought to 的反意疑问句，陈述部分是肯定的，疑问部分用shouldnt / oughtnt +主语。 He ought to know what to do, oughtnt he? / shouldnt he?5) 陈述部分有have to +v. (had to + v.)，疑问部分常用dont +主语（didnt +主语）。 We have to get there at eight tomorrow, dont we?6) 陈述部分的谓语是used to 时，疑问部分用didnt +主语或 usednt +主语。 He used to take pictures there, didnt he? / usednt he?7) 陈述部分有had better + v. 疑问句部分用hadnt you? Youd better read it by yourself, hadnt you?8) 陈述部分有would rather +v.，疑问部分多用 wouldnt +主语。 He would rather read it ten times than recite it, wouldnt he?9) 陈述部分有Youd like to +v. 疑问部分用wouldnt +主语。 Youd like to go with me, wouldnt you?10) 陈述部分有must 的疑问句，疑问部分根据实际情况而定。 He must be a doctor, isnt he? You must have studied English for three years, havent you? / didnt you? He must have finished it yesterday, didnt he?11) 感叹句中，疑问部分用be +主语。 What colours, arent they? What a smell, isnt it?12) 陈述部分由neither nor, either or 连接的并列主语时，疑问部分根据其实际逻辑意义而定。Neither you nor I am engineer, are we?13) 陈述部分主语是指示代词或不定代词everything, that, nothing, this, 疑问部分主语用it。 Everything is ready, isnt it?14) 陈述部分为主语从句或并列复合句，疑问部分有三种情况： a. 并列复合句疑问部分，谓语动词根据邻近从句的谓语而定。 Mr. Smith had been to Beijing for several times, he should have been in China now, shouldnt he? b. 带有定语从句，宾语从句的主从复合句，疑问部分谓语根据主句的谓语而定： He is not the man who gave us a talk, is he? He said he wanted to visit Japan, didnt he? c. 上述部分主句谓语是think, believe, expect, suppose, imagine等引导的定语从句，疑问部分与宾语从句相对应构成反意疑问句。 I dont think he is bright, is he? We believe she can do it better, cant she?15) 陈述部分主语是不定代词everybody, anyone, somebody, nobody, no one等，疑问部分常用复数they，有时也用单数he。 Everyone knows the answer, dont they? (does he?) Nobody knows about it, do they? (does he?)16) 带情态动词dare或need的反意疑问句，疑问部分常用 need (dare ) +主语。 We need not do it again, need we ? He dare not say so, dare you? 当dare, need 为实义动词时，疑问部分用助动词do + 主语。 She doesnt dare to go home alone, does she?17) 省去主语的祈使句的反意疑问句，疑问部分用will you。 Dont do that again, will you? Go with me, will you / wont you ?注意： Lets 开头的祈使句，后用shall we? Let us 开头的祈使句，后用will you? Lets go and listen to the music, shall we? Let us wait for you in the reading-room, will you ?18) 陈述部分是there be结构的，疑问部分用there省略主语代词。 There is something wrong with your watch, isnt there? There will not be any trouble, will there?19) 否定前缀不能视为否定词，其反意疑问句仍用否定形式。 It is impossible, isnt it? He is not unkind to his classmates,