條件句概念用法

A. 【英語語法：新概念】if引導的條件句（三種情況都要講出來）

樓主，你說的是不是虛擬語氣呀？
含有if條件句的虛擬語氣的構成如下：
1） 對現在虛擬： 條件句：一般過去時， 主句：could/would/should/ought to/might+動詞原形
例：if he were here now, we could have a meeting. 如果現在他在這兒，我們就可以開會了。(注意用的是he were。he was也可以，不過虛擬語氣里be動詞規范的用法還是多以were的形式出現 )
2）對過去虛擬： 條件句： 過去完成時，主句：could/would/should/ought to/might have done
例： if he had taken my advice, he shouldn't have failed in the exam. 如果他聽從我的建議，他考試就不會不及格。
3）對將來虛擬： 條件句：（1）were to do (2) should do (3)一般過去時 主句：could/would/should/ought to/might +動詞原形
例： If i had time/were to have time/should have time, I would visit my parents tomorrow. 如果我明天有時間，我就去看望我的父母

B. 請教英語條件句的用法

這是虛擬用法，表明「如果你現在到了北京的話，你就不可能找不到新東方學校」。
但是你現在不在新東方，
你現在到達新東方這件事與現實是相反的，所以用if sb +過去時

C. allow條件句的用法

concent courtesy empower grant permissibility permission permit
acknowledge accept acceptability

D. 條件狀語從句的用法以及注意事項！

不建議死記規則，語言講究的是感覺，多讀多背，感覺自然出來

E. 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。

F. 條件狀語從句中的連詞用法

條件狀語從句
通常由以下連詞引導：if, unless, on condition that, suppose, in case(如果，萬一), as /so long as(只要)等 如：
①If you are thirsty, water far away can』t help you.
遠水不解近渴。
②So long as we do not divorce ourselves from the masses, we are certain to be victorious.
只要我們不脫離群眾，我們就一定會勝利。
③You can』t expect the reception to be clear unless the radio set is properly tuned it.
如果不把收音機調好，你不可能指望收到清晰的播音。
④Suppose we can』t get the necessary equipment, what shall we do?
假設我們弄不到必要的設備，那我們怎麼辦？
⑤We』ll let you use the room on condition that you keep it clean and tidy.
我們可以讓你們用這個房間，如果你們能保持整潔的話。
⑥Send us a message in case you have any difficulty.
萬一有什麼困難請給我們一個信。

unless作連詞，表示「如果不」，「除非」，在意義上等於if…not, 在有些場合主要是指真實條件句，它引導的肯定式的條件狀語從句可以和if引導的否定式的條件狀語從句互換。

如：Unless you change your mind, I won』t be able to help you.
= If you don』t change your mind, I won』t be able to help you.
除非你改變你的想法，否則我不能幫助你。

unless不可用於假想的事情，因此，當if…not引導非真實條件狀語從句時，一般不可改用unless.
如：
If she weren』t so silly, she would understand.
如果她不那麼傻，她就會懂了。

G. 如何學習條件狀語從句（條件狀語的用法，結構，句型裝換）

這句話很正常啊,就是一個普通的if引導的條件狀從..
你參考下資料吧..

真實條件句用於陳述語氣，假設的情況可能發生，其中 if 是如果的意思。

時態關系

句型： 條件從句 主句

一般現在時 shall/will + 動詞原形

If he comes, he will bring his violin.

典型例題

The volleyball match will be put off if it ___.

A. will rain B. rains C. rained D. is rained

答案B。真實條件句主句為將來時，從句用一般現在時。

注意：

1） 在真實條件句中，主句不能用be going to表示將來，該用shall, will.

(錯) If you leave now, you are never going to regret it.

(對) If you leave now, you will never regret it.

2） 表示真理時，主句謂語動詞便不用shall (will) +動詞原形，而直接用一般現在時的動詞形式。

16.2 非真實條件句

1）時態：可以表示過去，現在和將來的情況。它的基本特點是時態退後。

a. 同現在事實相反的假設。

句型 ： 條件從句 主句

一般過去時 should( would) +動詞原形

If they were here, they would help you.

b. 表示於過去事實相反的假設。

句型： 條件從句 主句

過去完成時 should(would) have+ 過去分詞

If she had worked harder, she would have succeeded.

The rice would not have been burnt if you had been more careful.

If my lawyer had been here last Saturday, he would have prevented me from going.

If he had come yesterday, I should / would have told him about it.

含義：He did not come yesterday, so I did not tell him about it.

If he had not been ill and missed many classes, he would have made greater progress.

含義： He was ill and missed many lessons, so he did not make greater progress.

c. 表示對將來的假想

句型： 條件從句 主句

一般過去時 should+ 動詞原形

were+ 不定式 would + 動詞原形

should+ 動詞原形

If you succeeded, everything would be all right.

If you should succeed, everything would be all right.

If you were to succeed, everything would be all right.

16.3 混合條件句
主句與從句的動作發生在不同的時間，這時主，從句謂語動詞的虛擬語氣形式因時間不同而不同，這叫做混合條件句。

If you had asked him yesterday, you would know what to do now.

（從句與過去事實相反，主句與現在事實相反。）

If it had rained last night (過去), it would be very cold today (現在).

16.4 虛擬條件句的倒裝
虛擬條件句的從句部分如果含有were, should, 或had, 可將if省略，再把were, should或had 移到從句句首，實行倒裝。

Were they here now, they could help us.

=If they were here now, they could help us.

Had you come earlier, you would have met him

=If you had come earlier, you would have met him.

Should it rain, the crops would be saved.

=Were it to rain, the crops would be saved.

注意：

在虛擬語氣的從句中，動詞』be』的過去時態一律用"were"，不用was， 即在從句中be用were代替。

If I were you, I would go to look for him.
如果我是你，就會去找他。

If he were here, everything would be all right.
如果他在這兒，一切都會好的。

典型例題

_____ to do the work, I should do it some other day.

A. If were I B. I were C. Were I D. Was I

答案C. 在虛擬條件狀語中如果有were, should, had這三個詞，通常將if省略，主語提前, 變成 were, should, had +主語的形式。但要注意，在虛擬條件狀語從句中，省略連詞的倒裝形式的句首不能用動詞的縮略形式。如我們可說 Were I not to do., 而不能說 Weren』t I to do.

16.5 特殊的虛擬語氣詞：should

1） It is demanded / necessary / a pity + that…結構中的主語從句的謂語動詞要用should 加動詞原形， should 可省略。

句型：
(1)suggested

It is (2)important that…+ (should) do

(3) a pity

(1)suggested, ordered, proposed, required, demanded, requested, insisted； + (should) do

(2)important, necessary, natural, strange

a pity, a shame, no wonder

(3)It is suggested that we (should) hold a meeting next week.

It is necessary that he (should) come to our meeting tomorrow.

2）在賓語從句中的應用

在表示命令、建議、要求等一類動詞後面的從句中。

order, suggest, propose, require, demand, request, insist, command, insist + (should) do

I suggest that we (should) hold a meeting next week.

He insisted that he (should ) be sent there.

注意： 如suggest, insist不表示"建議" 或"堅持要某人做某事時"，即它們用於其本意"暗示、表明"、"堅持認為"時，賓語從句用陳述語氣。

The guard at gate insisted that everybody obey the rules.

判斷改錯:

（錯） You pale face suggests that you (should) be ill.

(對) Your pale face suggests that you are ill.

(錯) I insisted that you ( should) be wrong.

(對) I insisted that you were wrong.

3）在表語從句，同位語從句中的應用

在suggestion, proposal, idea, plan, order, advice等名詞後面的表語從句、同位語從句中要用虛擬語氣，即（should）+動詞原形。

My idea is that we (should) get more people to attend the conference.

I make a proposal that we (should) hold a meeting next week.

H. 英語中條件狀語從句的用法

條件狀語從句表示主句的動作發生的條件、假想、推測或意願。用連詞
if,
unless
和起連接作用的短語
except
that;
in
case
that;
on
condition
that;
provided/providing
that;
so/as
long
as;
suppose/supposing
that
引導。
用法:
1.從句表示的條件客觀上是現實的，常用陳述語氣，如:
If
the
stamp
is
torn,
it's
no
good
for
my
collection.如果郵票是破的，那我收集起來就沒有用了。
Suppose
all
the
doors
are
locked,
how
will
you
get
into
the
house?
假如所有的門都鎖上了，你怎麼會進到這所房子呢?
2.從句表示的條件同事實相違背或不可能實現，通常用虛擬語氣。如:
If
I
were
captain
of
a
ship,
I
would
take
you
on
a
voyage
round
the
world.如果我是一艘輪船的船長，我將帶你航海環游世界。
注意事項:
1.用一般現在時表示將來時。
The
meeting
will
be
held
out
of
doors
unless
it
rains.除非下雨，大會將在戶外舉行
2.用選擇完成時替代將來完成時。
If
I
have
made
a
mistake,
I
will
try
to
remedy
it.如果我犯了錯誤，我將會努力改正
3.will用在真實條件狀語從句中是情態動詞，表示意願或決心，而不是單純表示將來。
I
will
tell
you
if
you
will
come
on
Friday.如果你願意星期五來，我將告訴你。
還有其他一些情況，你暫時用不到，以後自己多注意。

I. if引導的真實條件句含義、結構、用法、例句，詳細。

if +主謂賓，抄主謂賓。大概是這么一襲個結構 例如 if you are late for school,you will be punished by the theacher.if 引領條件句，表示在此條件成立時，會發生的狀況。if 後可以跟現在完成時 一般現在時 一般過去式。用什麼根據後面的主句來決定。其實時態很好選擇 ，只要你分得清過去、現在和將來。例如上面一句 可以翻譯成：如果你遲到了，你將會受到老師的懲罰。很明顯，遲到是在受懲罰之前 而且是還未發生的事。再給你舉個例子，if you finished your homework,you would not have been punished by the theacher today.如果你昨晚做完作業了，今天就不會被老師罰了。這是對過去的假設，多聯系 多體會 你會很容易運用這些語句的 good luck every day!

J. 真實條件句和非真實條件句的含義及兩者在用法上的區別

你好復 很高興為你解答制 請看網址http://ke..com/view/26751.htm#1 http://ke..com/view/630435.htm
真實條件句實際上就是條件狀語從句，這個是真實的，有可能發生
但虛擬語氣則是不可能實現的，例如：如果我有100萬，我將周遊世界，這就是虛擬語氣，又叫非真實條件句 詳細組成看我給的網址 謝謝