条件状语从句，条件状语从句是什么

条件状语从句是什么

1、由引导词if或unless引导的状语从句叫做条件状语从句。

2、在英文中，条件是指某一件事情实现之后（状语从句中的动作），其它事情（主句中的动作）才能发生，通常译作“假如”、“如果”。（注意：在含有条件状语从句的复合句中，表示将来时态，主句是一般将来时态。

3、如有祈使句或情态动词，从句要用现在时态，主将从现原则。

（主将从现，将并非指将来时，还指表示将来含义的，跟着if后的那句话是从句。）

条件状语从句

条件状语从句，分为真实条件句和虚拟条件句。

这里介绍虚拟条件句：在虚拟条件中，谓语用陈述语气，表示现在以及将来的情况的状语从句，谓语形式为：should/could/would/might+动词原形。

虚拟条件句中动词“be”多用“were”，不管是什么人称，也不管是什么时态。

例1：If you looked at the Pacific from a space-capsule you might think the world was all water.

上句中，“looked at the Pacific from a space-capsule ”为从句，“you might think the world was all water.”为主句。

例2：If it were possible to do this, it still wouldn't be worth the trouble.

注意上句主语“it”的be动词为“were”，说明在虚拟条件句中，be动词始终为“were”，不管人称和时态。

例3：They all look as if they are wearing a uniform.

上句中，“as if”意为“就像……似的”，用以引导从句中的谓语多用虚拟语气。但有时也可以用陈述语气，尤其在“look”后面。

条件状语从句的主句为一般将来时态，而从句则是一般现在式的陈述句语序。

什么是条件从句?

条件状语从句分为两大类:真实条件句和虚拟条件句。当从句所表达的条件是有可能实现的、有可能是真实的条件时，用真实条件句;

如果从句所表达的条件是不可能实现的、与客观事实完全相反的条件或假设时，用虚拟条件句。一、混合虚拟条件句

如果条件从句的动作和主句的动作不是同时发生，主句和从句的谓语动词的

形式应分别根据各自所表示的 时间加以调整。这种句子叫做混合虚拟条件句。

If he had followed my advice,he would be quite all right now.(从句

述说过去，主句述说现在)二、省略if的倒装条件句

如果条件从句的谓语动词包含有were或助动词、情态动词

had,should,could，有时可将连词if省去，而将 条件从句的主语置于

were,had,should,could之后。这种用法主要用于书面语，

如:

Were I (=If I were) in your place,I wouldn't give it up so early.

如果我是你，我不会这么早就放弃。

条件状语从句和目的状语从句的区别

条件状语从句

条件状语从句就是用以表示“在某种条件下,会……”

常用if ,in case , on condition等词来引导

连接词主要有 if, unless, as/so long as, on condition that 等..

if 引导的条件句有真实条件句和非真实条件句两种.

主句用一般将来时,if或unless引导的条件状语从句用一般现在时.

固定搭配

unless = if not.

Let's go out for a walk unless you are too tired.

If you are not too tied, let's go out for a walk.

真实条件句,

如：If it rains tomorrow, we won”t go on a picnic.

非真实条件句是虚拟语气的一种,表示与事实相反,如：

If I were you, I would go with him.

if wrless,on condition that

so/as long as只要

时间状语从句

时间状语从句

（adverbial clause of time）

1.由when, while, as引导的时间状语从句.例如：

When you think you know nothing, then you begin to know something.当你以为自己一无所知的时候,你就是在开始知道一些事物了.

When truth is buried under the ground it grows, it chokes, it gathers such an explosive force that on the day it bursts out , it blows up everything with it.当真理被埋在地下的时候,它在生长,它感到压抑,它蓄存着这么一种爆炸性力量,一旦冒出,它就会炸破一切!

Strike while the iron is hot. 趁热打铁.

Will you watch my clothes while I have a swim. 我游泳的时候,请你照看一下我的衣服.

You can feel the air moving as your hand pushes through it. 当你的手在空气中挥动的时候,你就能感觉到空气在流动.

Our headmaster laughed as she spoke.我们的校长边谈边笑.

【区别】when, while和as的区别：when引导的从句的谓语动词可以是延续性的动词,又可以是瞬时动词.并且when有时表示“就在那时”.例如：

When she came in, I stopped eating.她进来时,我在吃饭.(瞬时动词)

When I lived in the countryside, I used to carry some water for him.当的住在农村时,我常常为他担水.（延续性的动词）

We were about to leave when he came in.我们就要离开,就在那时他进来了.

While引导的从句的谓语动作必须是延续性的,并强调主句和从句的动作同时发生（或者相对应）.并且while有时还可以表示对比.例如：

While my wife was reading the newspaper, I was watching TV. (was reading是延续性的动词,was reading和was watching同时发生)

I like playing football while you like playing basketball.我喜欢踢足球,而你喜欢打篮球.（对比）

As表示“一边……一边”,as引导的动作是延续性的动作,一般用于主句和从句动作同时发生；as也可以强调“一先一后.例如：

We always sing as we walk.我们总是边走边唱.（as表示“一边……一边”）

As we was going out, it began to snow.当我们出门时,开始下雪了.（as强调句中两个动作紧接着先后发生,而不强调开始下雪的特定时间）

2.由before和after引导的时间状语从句.注意before引导的从句不再用否定式的谓语,并且当before引导的从句位于主句之后,有时译成“就,才”.还要注意主句和从句之间的时间关系.当主句用将来时,从句总是用现在时；如果before引导的从句谓语用的是过去时,则主句动词多用过去完成时,这样以便体现动作发生的先后.After表示主句动作发生在从句动作之后.主句和从句的动作的时间关系正好与before引导的从句相反.例如：

It will be four days before they come back. 他们要过四天才能回来.

Einstein almost knocked me down before he saw me.爱因斯坦几乎把我撞倒才看到我.

My father had left for Canada just before the letter arrived.我父亲恰好在信到之前去加拿大了.

They had not been married four months before they were divorced. 他们结婚还不到四个月就离婚了.

After you think it over, please let me know what you decide.你仔细考虑过以后,告诉我你是怎样决定的.

After we had finished the work, we went home.完成工作之后,我们回家了.（从句用过去完成时,主句用一般过去时）

3.由till或until引导的时间状语从句.till和until一般情况下两者可以互换,但是在强调句型中多用until.并且要注意的是：如果主句中的谓语动词是瞬时动词时,必须用否定形式；如果主句中的谓语动词是延续性动词时,用肯定或否定形式都可以,但表达的意思不同.例如：

I didn't go to bed until（till） my father came back.直到我父亲回来我才上床睡觉.

It was not until the meeting was over that he began to teach me English.直到散会之后他才开始教我英语.

I worked until he came back.我工作到他回来为止.

I didn't work until he came back.他回来我这才开始工作.

Please wait until I arrived.在我到达之前请等我.

4.由since引导的时间状语从句. since引导的从句的谓语动词可以是延续性的动词,又可以是瞬时动词.一般情况下,从句谓语动词用一般过去时,而主句的谓语动词用现在完成时.但在It is ＋时间＋since从句的句型中,主句多用一般现在时.例如：

I have been in Beijing since you left. 自从你离开以来,我一直在北京了.

Where have you been since I last saw you? 自上次我和你见面以后,你到哪里去了?

It is four years since my sister lived in Beijing. 我妹妹不在北京住有四年了.

It is five months since our boss was in Beijing.我们老板离开北京有五个月了.

5.由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引导的时间状语从句.这些连词都表示“一……就”.例如：

I will go there directly I have finished my breakfast. 吃完早饭,我立即到那里去.

The moment I heard the news, I hastened to the spot.我一听到消息,马上赶到了出事地点.

As soon as I reach Canada, I will ring you up. 我一到加拿大,就给你来电话.

【注意】hardly(scarcely, rarely)…when / before, no sooner…than相当于as soon as之意.主句用过去完成时,从句用一般过去时.当hardly, scarcely, rarely和no sooner位于句首时,主句应用倒装语序.例如：

He had no sooner arrived home than he was asked to start on another journey. 他刚到家,就被邀请开始另一旅程.

No sooner had the sun shown itself above the horizon than he got out of bed to commence work.太阳刚从地平线上升起,他就起床劳动去了.

Hardly had I sat down when he stepped in.我刚坐下,他就进来了.

He had hardly fallen asleep when he felt a soft touch on his shoulder.这个阿拉伯人刚要入睡就感到肩膀上被轻轻一触.

6.由by the time引导的时间状语从句.注意时态的变化：在一般情况下,如果从句的谓语动词用一般过去时,主句的谓语动词用过去完成时；如果主句的谓语动词用一般现在时,主句的谓语动词用将来完成时.例如：

By the time you came back, I had finished this book.到你回来时,我已经写完这本书了.

By the time you come here tomorrow, I will have finished this work. 你明天来这儿的时候,我将已经完成此工作了.

7.由each time, every time和whenever引导的时间状语从句.例如：

Each time he came to Harbin, he would call on me. 他每次来哈尔滨,总是来看我.

Whenever that man says“To tell the truth”, I suspect that he's about to tell a lie.每当那个人说“说实在话”的时候,我猜想他就要说谎了.

You grow younger every time I see you. 每次遇到你,见你更年轻了.

8.由as long as和so long as引导的时间状语从句.这两个连词表示“有多久……就多久”.例如：

You can go where you like as long as you get back before dark. 你可以随意到哪里去,只要在天黑以前回来就行.

I will fight against these conditions as long as there is a breath in my body! 只要我一息尚存,我就要反对这种境况.

这是一般现在,一般过去,现在进行,过去进行,现在完成,过去完成,现在完成进行,一般将来,过去将来时的时间状语:

1.Often,usually----------动词原型do,does,am,is, are

2.yesterday,last Sunday,in the past-------动词过去式did,was,were

3.now--------be+doing

4.while,at that time,-------was doing,were doing

5.since从句,for 2 days,------have done,have been

6.by+过去的某个时间点----had done,had been

7.与现在完成相似-------have been+持续动词ing形式

8.一切表示将来的时间状语,in+一段时间-------将来要发生的一般性动作,

will,shall+原型

9.与一般将来时相似-----------would+原型

简单来说呢

就是

时间状语从句是用when \while引导的

条件状语从句是用if引导的

以上就是关于条件状语从句，条件状语从句是什么的全部内容，以及条件状语从句是什么的相关内容,希望能够帮到您。