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. after B. before C. since D. 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。
结构 从句中谓
语动词的
形式
It is +时间段+since
从句
一般过去（到现在为止）做
It is three years since the war
时 某事已有多长时间
broke out.
了
It was+时间段+since过去完成（到过去某时为
从句 时
It was two years since he had
含义 例句
止）做某事已有多
left here.
长时间了
It was +时间段
+before从句
It was not +时间段
+before从句
It will be +时间段
+before从句
一般过去过了多长时间
时 才……
It was a long time before I got
to sleep again.
It wasn’t long before he told
me about this affair
It will be five years before we
meet again.
It won’t three hours before he
arrives at the bus stop.
一般过去没过多长时间
时 就……
一般现在要过了多长时间
时 才……
It will be not +时间段一般过去没过多长时间
+before从句 时 就……

It iswas +时间点
+when引导的定语从
句
It iswas+时间状语
+that引导的强调句
It’s time that+从句

做某事的时间是什
It was eight o’clock in the
么时间
morning when he went
shopping.

正是在某个时间，
It was at eight o’clock in the
某事发生了
morning that he went shopping.
一般过去
是该做某事的时候
It is time that I went (should
时（或
should+动
词原形）
了
go) to pick up his daughter.
It is the
现在完成某人第一二三次
It is my first time (that) I have
做……
visited the Great Wall. firstsecondthird time
时
+that从句
ItThisThat was the
过去完成某人第一二三次
It was the second time that the
firstsecondthird time
时
+that从句
总结一
在时间 + 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。
做……
film had been shown in this
cinema

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)

例2：-Did Jack come back early last night？
- was not yet eight o'clock________he arrived home.


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：
ishas been + 时间段 + since + 一般过去时
例1：It ishas been 10 years 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.
+ 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.
+ 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)

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)
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.
d arrived arrived
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 cameshould 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。
be + 时间(被强调部分) + that
例1：It was at 6 o'clock that we heard the noise.
例2：It was 3 years 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 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。
【链接训练】
was not until 1936________basketball became a regular part of
the Olympic Games.

will not be________we meet again.
before long
after y after
3.──He was nearly drowned once. ──When was________？
──________was in 1998 when he was in middle school. It
;This It This
was evening________we reached the little town of Winchester.(04
天津)

ists say it may be five or six years_it is possible to test
this medicine on human patients.

was______I met in London.
years that many years since many years
ago when years ago that
7. -What was the party like？
-'s years_____I enjoyed myself so much.

was about 600 years ago___the first clock with a face and
an hour hand was made.

9. I'm sorry you've been waiting so long, but it'll still be some time ____ Brian get
back.
A. before B. since C. till D. After

10.-Did Jack come back early last night？ - was not yet eight
o'clock________he arrived home.




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 ishas been + 时间段 + since + 一般过去时
例如：It ishas been 5 years 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：It was 10 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。
+ 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.
+ 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)

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：It

was+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.
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) you
cameshould 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 and formed 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：
be + 时间(被强调部分) + that 如：It was at 6 o'clock that
we heard the noise.（强调句） It was 3 years ago that he joined
the army.（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be +时间+conj句型 在各类考试和历届高考试题中
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 since

I 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 much
A. after 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...句型和
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 until
C: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
与句型比较:前后时态一致 与、句型强调的是时间段，而
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 was this 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 Tom this morning