條件從句語法

『壹』 if引導的條件狀語從句例句

引導條件狀語從句最常用的連詞是if,由if引導的條件狀語從句表示在某種條件下某事很可能發生。專如:
If
you
ask
him,
he
will
help
you.如果你請他幫忙屬,他會幫你的。
If
you
fail
in
the
exam,
you
will
let
him
down.如果你考試不及格,你會讓他失望的。
另外,if從句還表示不可實現的條件或根本不可能存在的條件,也就是一種虛擬的條件或假設,從句多用一般過去時或過去完成時。如:
If
I
were
you,
I
would
invite
him
to
the
party.如果我是你,我會邀請他參加聚會。
I
would
have
arrived
much
earlier
if
I
had
not
been
caught
in
the
traffic.如果沒有堵車,我會到的早一點兒。

『貳』 如何判斷條件狀語從句

由引導詞if或unless引導的狀語從句，叫做條件狀語從句。通過這兩個單詞就可以判回斷出來的。答

在英文中，條件是指某一件事情實現之後就是狀語從句中的動作，其它事情（主句中的動作）才能發生，通常譯作「假如」、「如果」。

『叄』 什麼是條件狀語從句和時間狀語從句

條件狀語從句
條件狀語從句就是用以表示「在某種條件下,會……」
常用if ,in case , on condition等詞來引導
連接詞主要有 if, unless, as/so long as, on condition that 等..
if 引導的條件句有真實條件句和非真實條件句兩種.
主句用一般將來時,if或unless引導的條件狀語從句用一般現在時.
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.
真實條件句,
如：If it rains tomorrow, we won」t go on a picnic.
非真實條件句是虛擬語氣的一種,表示與事實相反,如：
If I were you, I would go with him.
if wrless,on condition that
so/as long as只要
時間狀語從句
時間狀語從句
（adverbial clause of time）
1.由when, while, as引導的時間狀語從句.例如：
When you think you know nothing, then you begin to know something.當你以為自己一無所知的時候,你就是在開始知道一些事物了.
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.當真理被埋在地下的時候,它在生長,它感到壓抑,它蓄存著這么一種爆炸性力量,一旦冒出,它就會炸破一切!
Strike while the iron is hot. 趁熱打鐵.
Will you watch my clothes while I have a swim. 我游泳的時候,請你照看一下我的衣服.
You can feel the air moving as your hand pushes through it. 當你的手在空氣中揮動的時候,你就能感覺到空氣在流動.
Our headmaster laughed as she spoke.我們的校長邊談邊笑.
【區別】when, while和as的區別：when引導的從句的謂語動詞可以是延續性的動詞,又可以是瞬時動詞.並且when有時表示「就在那時」.例如：
When she came in, I stopped eating.她進來時,我在吃飯.(瞬時動詞)
When I lived in the countryside, I used to carry some water for him.當的住在農村時,我常常為他擔水.（延續性的動詞）
We were about to leave when he came in.我們就要離開,就在那時他進來了.
While引導的從句的謂語動作必須是延續性的,並強調主句和從句的動作同時發生（或者相對應）.並且while有時還可以表示對比.例如：
While my wife was reading the newspaper, I was watching TV. (was reading是延續性的動詞,was reading和was watching同時發生)
I like playing football while you like playing basketball.我喜歡踢足球,而你喜歡打籃球.（對比）
As表示「一邊……一邊」,as引導的動作是延續性的動作,一般用於主句和從句動作同時發生；as也可以強調「一先一後.例如：
We always sing as we walk.我們總是邊走邊唱.（as表示「一邊……一邊」）
As we was going out, it began to snow.當我們出門時,開始下雪了.（as強調句中兩個動作緊接著先後發生,而不強調開始下雪的特定時間）
2.由before和after引導的時間狀語從句.注意before引導的從句不再用否定式的謂語,並且當before引導的從句位於主句之後,有時譯成「就,才」.還要注意主句和從句之間的時間關系.當主句用將來時,從句總是用現在時；如果before引導的從句謂語用的是過去時,則主句動詞多用過去完成時,這樣以便體現動作發生的先後.After表示主句動作發生在從句動作之後.主句和從句的動作的時間關系正好與before引導的從句相反.例如：
It will be four days before they come back. 他們要過四天才能回來.
Einstein almost knocked me down before he saw me.愛因斯坦幾乎把我撞倒才看到我.
My father had left for Canada just before the letter arrived.我父親恰好在信到之前去加拿大了.
They had not been married four months before they were divorced. 他們結婚還不到四個月就離婚了.
After you think it over, please let me know what you decide.你仔細考慮過以後,告訴我你是怎樣決定的.
After we had finished the work, we went home.完成工作之後,我們回家了.（從句用過去完成時,主句用一般過去時）
3.由till或until引導的時間狀語從句.till和until一般情況下兩者可以互換,但是在強調句型中多用until.並且要注意的是：如果主句中的謂語動詞是瞬時動詞時,必須用否定形式；如果主句中的謂語動詞是延續性動詞時,用肯定或否定形式都可以,但表達的意思不同.例如：
I didn't go to bed until（till） my father came back.直到我父親回來我才上床睡覺.
It was not until the meeting was over that he began to teach me English.直到散會之後他才開始教我英語.
I worked until he came back.我工作到他回來為止.
I didn't work until he came back.他回來我這才開始工作.
Please wait until I arrived.在我到達之前請等我.
4.由since引導的時間狀語從句. since引導的從句的謂語動詞可以是延續性的動詞,又可以是瞬時動詞.一般情況下,從句謂語動詞用一般過去時,而主句的謂語動詞用現在完成時.但在It is ＋時間＋since從句的句型中,主句多用一般現在時.例如：
I have been in Beijing since you left. 自從你離開以來,我一直在北京了.
Where have you been since I last saw you? 自上次我和你見面以後,你到哪裡去了?
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.我們老闆離開北京有五個月了.
5.由as soon as, immediately, directly, instantly, the moment, the instant, the minute, 等引導的時間狀語從句.這些連詞都表示「一……就」.例如：
I will go there directly I have finished my breakfast. 吃完早飯,我立即到那裡去.
The moment I heard the news, I hastened to the spot.我一聽到消息,馬上趕到了出事地點.
As soon as I reach Canada, I will ring you up. 我一到加拿大,就給你來電話.
【注意】hardly(scarcely, rarely)…when / before, no sooner…than相當於as soon as之意.主句用過去完成時,從句用一般過去時.當hardly, scarcely, rarely和no sooner位於句首時,主句應用倒裝語序.例如：
He had no sooner arrived home than he was asked to start on another journey. 他剛到家,就被邀請開始另一旅程.
No sooner had the sun shown itself above the horizon than he got out of bed to commence work.太陽剛從地平線上升起,他就起床勞動去了.
Hardly had I sat down when he stepped in.我剛坐下,他就進來了.
He had hardly fallen asleep when he felt a soft touch on his shoulder.這個阿拉伯人剛要入睡就感到肩膀上被輕輕一觸.
6.由by the time引導的時間狀語從句.注意時態的變化：在一般情況下,如果從句的謂語動詞用一般過去時,主句的謂語動詞用過去完成時；如果主句的謂語動詞用一般現在時,主句的謂語動詞用將來完成時.例如：
By the time you came back, I had finished this book.到你回來時,我已經寫完這本書了.
By the time you come here tomorrow, I will have finished this work. 你明天來這兒的時候,我將已經完成此工作了.
7.由each time, every time和whenever引導的時間狀語從句.例如：
Each time he came to Harbin, he would call on me. 他每次來哈爾濱,總是來看我.
Whenever that man says「To tell the truth」, I suspect that he's about to tell a lie.每當那個人說「說實在話」的時候,我猜想他就要說謊了.
You grow younger every time I see you. 每次遇到你,見你更年輕了.
8.由as long as和so long as引導的時間狀語從句.這兩個連詞表示「有多久……就多久」.例如：
You can go where you like as long as you get back before dark. 你可以隨意到哪裡去,只要在天黑以前回來就行.
I will fight against these conditions as long as there is a breath in my body! 只要我一息尚存,我就要反對這種境況.
這是一般現在,一般過去,現在進行,過去進行,現在完成,過去完成,現在完成進行,一般將來,過去將來時的時間狀語:
1.Often,usually----------動詞原型do,does,am,is, are
2.yesterday,last Sunday,in the past-------動詞過去式did,was,were
3.now--------be+doing
4.while,at that time,-------was doing,were doing
5.since從句,for 2 days,------have done,have been
6.by+過去的某個時間點----had done,had been
7.與現在完成相似-------have been+持續動詞ing形式
8.一切表示將來的時間狀語,in+一段時間-------將來要發生的一般性動作,
will,shall+原型
9.與一般將來時相似-----------would+原型
簡單來說呢
就是
時間狀語從句是用when \while引導的
條件狀語從句是用if引導的

『肆』 If條件從句的語法

正確。個人覺得就是如此。

『伍』 請問if 引導的條件狀語從句有幾種形式

1. 主將從現 I will help you if you help me.
2. 主現從現回 If you help others, they are likely to help you in return.
3. 虛擬答 If I were you , I would not do that.
If I had been you, I would have gone there.
If I were/ should be/ were to be you , I would go there.

『陸』 什麼叫條件狀語從句

在復合句中，由從句表示的狀語叫做狀語從句。它可以用來修飾主語中的動詞.形容詞.副詞等。根據它表達的意思，狀語從句可以分為時間狀語從句，地點狀語從句，條件狀語從句，比較狀語從句，目的狀語從句，結果狀語從句和讓步狀語從句等。由連接詞if或unless引導的狀語從句叫做條件狀語從句。在英文中，條件是指某一件事情實現之後（狀語從句中的動作），其它事情（主句中的動作）才能發生，通常譯作「假如」。（注意：在含有條件狀語從句的復合句中，表示將來時態，主句是一般將來時態，從句要用一般現在時[主將從現原則]，並且，切記緊跟著if的那句話是從句。）
語法引導條件狀語從句最常用的連詞是if,由if引導的條件狀語從句表示在某種條件下某事很可能發生。如:
If
you
ask
him,
he
will
help
you.如果你請他幫忙,他會幫你的。
If
you
fail
in
the
exam,
you
will
let
him
down.如果你考試不及格,你會讓他失望的。
從上述例句可以看出if,
unless,
on
condition
(that),
supposing,
provided等詞引導的條件狀語從句,主從句條件關系分明,結構清晰。
但有些句子,雖沒有含條件關系的連詞,卻也隱含著條件關系,這些句子常用一些詞,如but
for,
without等引出一個介詞結構來表示條件,條件常常是虛擬的,或與事實相反的假設。

『柒』 條件狀語從句的條件狀語用法

條件狀語從句的用法是：

1. if 表示正面的條件， 意為「如果」； unless (=if not) 表示負面的條件， 意為「除非， 如果不」。例如： If you ask him, he will help you. 如果你請求他， 他會幫助你。// If you had come a few minutes earlier, you would have met him. 要是你早來幾分鍾就碰到他了。(本例句屬於第8章中介紹過的以虛擬語氣表示非真實條件句的情況。) // He is sure to come unless he has some urgent business. 他一定會來， 除非他有急事。

2. in case， on condition that， providing， provided (that)， supposing， suppose (that)等詞彙意思相近， 指「假如， 假使， 在……條件下」(比if更為書面化)。例如： In case he comes, let me know. 如果他來的話， 告訴我一聲。// I shall give you my dictionary on condition that you return it tomorrow. 我將把我的字典給你， 如果你明天要還的話。 // I will go, providing/provided (that) my expenses are paid. 只要我的費用有人付， 我就去。 // Suppose/Supposing (that) he does not come, what shall we do? 他要是不來， 我們該怎麼辦？

3. as long as (=so long as) 表示充分必要條件， 引導語氣強烈的條件狀語從句時， 意為「只要」。例如： I will cooperate as long as I am notified on time. 只要及時告訴我， 我就會合作。 // You may use the book so long as you will return it on time. 只要你准時還， 你就可以借這本書。