（完整版）It+时间+从句的区别完整解释

It+时间+从句”考点透视请看下⾯⼀道题:

The field research will take Joan and Paul about five months; it will be a long time_____ we meet them again.A. afterB. beforeC. sinceD. when

这是2007年安徽的⼀道⾼考题，其实质上是通过“it + be+从句”这⼀句型来考查了连词的⽤法。在该结构中连词的选择是有规可循的，主要是由主句、从句中的谓语动词的时态来确定的。下⾯通过下表⽐较（尤其是对主从中时态的⽐较）就能很容易的掌握。

总结⼀

在\" It +be+ 时间+ 从句\"结构中，引导从句的从属连词有before, that, since, until （till ）, when 等。这⼀结构是近⼏年⾼考常考的知识点，现将它们的⽤法⼩结如下：

⼀、It +be （not ）+ 时间段+before 从句。其中的主句是肯定式时，意为\"过多长时间才......\"；主句是否定式时，意为\"没过多久就......\"。

例如：1. It was not long before the whole country rose and drove the Austrian soldiers from their homeland.2.It may be five or six years before the new medicine is tested on human beings.3.It was two months before he designed the bridge.

⼆、It +will be （was ）+ 时间段+until 从句若主句中⽤⼀般将来时，则从句中⽤⼀般现在时，意思是从现在起到从句中谓语动词表⽰的动作发⽣时还有多长时间；若主句中⽤⼀般过去时，则从句中也⽤⼀般过去时，意思是从过去某⼀时间起到从句中谓语动词表⽰的动作发⽣还有多长时间。

例如：1. It will be ten days until my birthday comes.

2.It was only five minutes until her husband came back from work.

注意：结构\"⼀\"与结构\"⼆\"在肯定句中⼏乎可以通⽤。但是，若从句中谓语动词表⽰的将来动作⼀定或预期肯定会发⽣，则多⽤until 引导从句；若从句中谓语动词表⽰的将来动作在客观上并⾮⼀定要发⽣时，则多⽤before 引导从句。

三、It +is / has been （was ）+ 时间段+since 从句在这⼀结构中，主句常⽤⼀般现在时、现在完成时或⼀般过去时。如果since 引导的状语从句中的谓语动词为⾮延续性动词，则表⽰\"⾃从状语从句中的动作发⽣以后，时间过不了多久\"。例如：1. It is two years since Jim came to China.2. It has been three years since they got married.

如果since 从句中的谓语动词为延续性动词，则表⽰\"⾃从从句谓语动词表⽰的动作结束以来，时间已过了多久\"。例如：3. It is / has been a year since he smoked.

四、It +is / was + 时间点+when 从句在这⼀结构中，时间之前没有介词，从句为when 引导的时间状语从句。从句常⽤⼀般过去时，意为\"当某事发⽣时，时间是......\"。

例如：1. It was October 1st, 1949 when the People's Republic of China was founded.2.What time was it when you got to school?

五. It is /was + 时间状语+that 从句这是⼀个强调句型，被强调的部分是时间状语。表⽰\"正是在某个时间，某事发⽣了\"。例如1. It was ten years ago that he joined the army.2.It was yesterday afternoon that I met him in the street.

六、It is / was +first time / second time + （that ）从句在这⼀结构中，time 前⾯常⽤序数词来修饰，that 引导的是定语从句，从句中常⽤现在完成时态或过去完成时态，表⽰\"这是第......次做某事\"。例如：1. This is the first time in my life that I have come to Beijing.2.It was the third time that he had asked the same question.

七、It is （high ）time +that 从句在这⼀结构中，that 从句中的谓语动词常⽤虚拟语⽓，即\" should + 动词原形\"或⽤动词的过去式，表⽰\"该做某事了\"。

例如：1. It is high time that we began our work.2. It is time that he left the place.【链接训练】

例1：It is almost five years_____we saw each other last time.(05北京)A.beforeB.sinceC.afterD.when

例2：-Did Jack come back early last night？

-Yes.It was not yet eight o'clock________he arrived home. A.before B.when C.that D.until总结⼆

这类考题出现频率较⾼，考⽣⼜极易混淆，在复习中做出归类⾮常必要：1.It is/has been+时间段+since+⼀般过去时

例1：It is/has been10years since he came here.这类句型可转化为：=Ten years has passed since he came here. 这⼀句型可扩展为：It was+时间段+since(从句⽤过去完成时)

例2：It was years since he had arrived in China.(过去是+since+过去完成时) 需要注意的是since从句的谓语动词⼀般是⾮延续性动词，但有时也可⽤延续性动词或表⽰状态的词，此时需要注意句⼦的翻译：例3：It is three years since she came to our class.It is three years since she was in our class.

2.It+was+时间点+when clause(从句谓语⽤⼀般过去时) will be+时间点+when clause(从句谓语⽤⼀般现在时表将来)例1：It was already evening when he came back.例2：It will be midday when they get home.

3.It+will(not)be+时间段+before+现在时was(not)+时间段+before+过去时例1：It will be another year before he comes here.

例2：It was some time______we realized the truth.(2005⼭东24) A.when B.until C.since D.before

该句型中before前常⽤时间段，表⽰\"...之后才...\"\"在...之前就...\";有时before 前也可以⽤时间点，此时突出表⽰动作的变化。试

⽐较：

例3：It was evening before we reached the little town of Tailstocks. 当我们到达Tailstocks时已经⿊了。(到达前天还没有⿊)4.It/This is+the+序数词+时间+定语从句(从句⽤完成时)

例1：It is the first time(that)I have been here.(定语从句) 该句型可扩展为：It was+序数词+时间+定语从句(从句⽤过去完成时)例2：It was the second time he had been out with her alone.例3：It's the second time you________late this week.A.arriveB.arrivedC.have arrivedD.had arrived

5.It is+(high)time+that+did(虚拟语⽓)

例1：It is(high)time(that)we stopped pollution. 其中that引导得从句中也可⽤should+V(原型)例2：It is(high)time(that)you came/should come here. 写作中表⽰建议时也常可⽤这类句型。

例3：It's high time we took measures to solve this problem.注意应将以上5种句型与强调时间的强调句型的区别。6.It be+时间(被强调部分)+that

例1：It was at6o'clock that we heard the noise.

例2：It was3years ago that he joined the army. 最简单的判断⽅法是：当表⽰时间的词前有介词或者后有副词时，⼀定是强调结构，必⽤that。试⽐较下⾯句式与强调句的不同之处：It was already ten o'clock when he arrived. It is ten years since I metyou last. It was quite some

time before he found the elephant at all. 以上⼏句中时间前⽆介词后没副词故不是强调句型。【链接训练】

1.It was not until1936________basketball became a regular part of the Olympic Games.A.thatB.whenC.whichD.then

2.It will not be________we meet again.A.long beforeB.before longC.soon afterD.shortly after

3.──He was nearly drowned once. ──When was________？──________was in1998when he was in middle school. A.that;ItB.this;ThisC.this;ItD.that;This

4.It was evening________we reached the little town of Winchester.(04天津)A.that

B.untilC.sinceD.before

5.Scientists say it may be five or six years_it is possible to test this medicine on human patients.A.sinceB.afterC.beforeD.when

6.It was______I met Mr.Smith in London.A.many years thatB.for many years sinceC.since many years ago whenD.many years ago that7. -What was the party like？

-Wonderful.It's years_____I enjoyed myself so much.A.afterB.beforeC.whenD.since

8.It was about600years ago___the first clock with a face and an hour hand was made.A.thatB.untilC.beforeD.when

9. I'm sorry you've been waiting so long, but it'll still be some time ____ Brian get back.A. beforeB. sinceC. tillD. After

10.-Did Jack come back early last night？-Yes.It was not yet eight o'clock________he arrived home.A.beforeB.whenC.thatD.until总结三

这类考题出现频率较⾼，考⽣⼜极易混淆，在复习中做出归类⾮常必要：1.It is/has been+时间段+since+⼀般过去时

例如：It is/has been5years since he came to our school. 这⼀句型可引申为：It was+时间段+since(从句⽤过去完成时)如：Itwas10 years since he had arrived in China. 需要注意的是since从句的谓语动词⼀般是⾮延续性动词，但有时也可⽤延续性动词或表⽰状态的词，此时需要注意句⼦的翻译：例如：It is three years since she came to our class.It is three years since she was in our class.

总之，在翻译此类句⼦的时候我们要记住⼀点，那就是\"⾃从这⼀动作结束以来\"，只要记住这⼀点我们就⽐较好理解句⼦了。2.It+was+时间点+when clause(从句谓语⽤⼀般过去时)It will be+时间点+when clause(从句谓语⽤⼀般现在时表将来)例如：It was already eight o'clock when he came back.It will be midday when they get home.3.It+will(not)be+时间段+before+现在时It was(not)+时间段+before+过去时

例如：It will be another year before he comes here. It was some time______we realized the truth.(05⼭东24)A.whenB.untilC.sinceD.before

4.It/This is+the+序数词+时间+that从句(从句⽤完成时)例如：It is the first time that I have been here. 该句型可引申为：Itwas+序数词+时间+that从句(从句⽤过去完成时)

例如：It was the second time that he had been out with her alone.5.It is+(high)time+that+did(虚拟语⽓)

例如：It is(high)time(that)we stopped pollution. 其中that引导得从句中也可⽤should+V(原型)如：It is(high)time(that)youcame/should come here. 写作中表⽰建议时也常可⽤这类句型。如：It's high time we broke away from the bad habits andformed good ones. 注意应将以上5种句型与强调时间的强调句型的区别：

6.It be+时间(被强调部分)+that如：It was at6o'clock that we heard the noise.（强调句）It was3years ago that he joined thearmy.（⾮强调句）最简单的判断⽅法是：当表⽰时间的词前有介词或者后有副词时，⼀定是强调结构，必⽤that。试⽐较下⾯句式与强调句的不同之处：It was already ten o'clock when he arrived. It is ten years since I met you last.It was quite some time before he found the elephant at all. 以上⼏句中时间前⽆介词后没副词故不是强调句型。总结四

探究语法填空中\"It be +时间+conj\"句型在和历届⾼考试题中\"it+be+time+conj\"句型以不同的形式出现,往往使同学们顾此失彼,⼀头雾⽔,原因在于没有搞清楚各个句型的特点及实质,现结合历届⾼考题分别予以探究。(⼀)It is +时间段+since+从句It has been +时间段+since+从句此句型的要点：

(1) 注意since前后句⼦时态.since前的时态为is或has been,后的时态为⼀般过去时Eg: It is(has been) ten years since I joined the army 译为:

(2)since后的动词若为延续性或状态性动词,应译为否定或相反,若为短暂性动词按字⾯意思翻译.Eg: It is(has been) ten years since I was a teacher =It is(has been) ten years sinceI left the army 译为:.

It is ten years since I smoked =It is ten years since I stopped smoking 译为:

【链接训练】:1、－What was the party like？－Wonderful. It's years____ I enjoyed myself so muchA. after

B.before C:when D:since

2、I live in Beijing now, that's to say, it's ten years since I ____Beijing.A:lived in B:left for C:left D:was in

3、I'm a teacher now, that's to say, it is ten years since I___ a teacher.A: have been B: was C:became D:turned

（⼆）It will be +时间段+before+⼀般现在时的从句\"要过多久/ 不久...才...\"

It was +时间段+before+⼀般过去时的从句\"过了多久才...\" \"before\"句型和\"since\"句型的共性都加时间段,差异在于前后的时态和翻译。

Eg: ① It will be ten years before I return home. 译为:② It was ten years before he found his lost boy. 译为:

【链接训练】:1、It is reported that it may be two or three months_____it is possible to test this medicine on animals.A:since B:after C:before D:when

2、－How long do you think it will be ______ China sends a manned spaceship to the moon？－Perhaps two or three years A:when B:until C:that D:before

3、How long do you think ____ the computer company brings out a new product？(2005.上海)A: it will be before B:will it be untilC:will it be when D: it will be that

（三）It will be+时间点+when+⼀般现在时的从句It was +时间点+when+⼀般过去时的从句

与\"before\"句型⽐较:前后时态⼀致与\"since\"、\"before\"句型强调的是时间段，⽽\"when\"句型强调的是时间点。Eg: ① It will be midnight when I return home. 译为:② It was noon when the accident happened 译为:

练习:1、___ was 1979 ____ I graduated from university (1997.上海)A:That; that B:It; that C:That; when D:It; when

2、It was breakfast _____ our teacher punished me (2004.北京)A:when B: until C:since D: before

(四)It is(was)+时间点+that的强调句型强调句仅是形似，与\"when\"句型的⽐较很明显：1. 强调句时间点部分通常带有介词；

2. 去掉it is(was)......that之后，句⼦整合成⼀个完整的句⼦。

Eg:①It was in the morning that I was robbed in the street. （删除后还原：I was robbed in the street in the morning.）=It wasthis morning that I was robbed in the street.

②It was at 7:00 that I met Tom this morning. （删除后还原：I met Tom this morning at 7:00.）=It was 7:00 when I met Tomthis morning