条件状语从句的条件状语用法

如题所述

unless = if...not.
e.g. Let's go out for a walk unless you are too tired.
If you are not too tired,let's go out for a walk.
if 引导的条件句有真实条件句和非真实条件句两种:
真实条件句
如:If it rains tomorrow,we won’t go on a park 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.
so/as long as只要
由as (so) long as,in case引导。
So long as you’re happy,it doesn’t matter what you do.
只要你高兴,你做什么都没有关系。
You may borrow my book as long as you keep it clean.
只要你保持书的清洁,你就可以把我的书借去。
Take your umbrella in case it rains.
带着你的伞吧,以防下雨。
例句
引导条件状语从句的连词有:if(如果),unless(除非;如果不),as long as(除非;只要),supposing(假设),on condition that(条件是),in case(如果)。
【例】
You can't learn English well unless you work hard.
除非你努力学习,否则你学不好英语。
You can use my bike on condition that you return it by Friday.
你可以使用我的自行车,条件是你星期五以前还。
1)学习条件状语从句应注意以下几点:
⑴条件状语从句中一般不使用将来时态,尽管主句使用将
来时态,而从句用一般现在时或现在完成时。
【例】
I will come to see you if I have time.
我有时间,我就来看你。
If the rain stops,I shall go out for a walk.
如果雨停了,我就出去散步。
⑵注意条件状语从句在虚拟语气中的使用。
【例】
If I were to I should first of all get the experts to discuss the plan.
如果我真的想做这事,我首先会找专家们讨论我的计划。
⑶条件状语从句中的省略。
【例】
Come tomorrow if possible. 可能的话,明天来。
I will buy a DVD set if necessary.

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第1个回答  2016-05-30
条件状语从句的用法:
条件状语从句表示条件, 现将其在高考卷中的常见引导词介绍如下:
1、if 表示正面的条件, 意为“如果”; unless (=if not) 表示负面的条件, 意为“除非, 如果不”。
例如:
If you ask him, he will help you. 如果你请求他, 他会帮助你。
If you had come a few minutes earlier, you would have met him. 要是你早来几分钟就碰到他了。
He is sure to come unless he has some urgent business. 他一定会来, 除非他有急事。

2. in case, on condition that, providing, provided (that), supposing, suppose (that)等词汇意思相近, 指“假如, 假使, 在……条件下”(比if更为书面化)。
例如:
In case he comes, let me know. 如果他来的话, 告诉我一声。
I shall give you my dictionary on condition that you return it tomorrow. 我将把我的字典给你, 如果你明天要还的话。
I will go, providing/provided (that) my expenses are paid. 只要我的费用有人付, 我就去。Suppose/Supposing (that) he does not come, what shall we do? 他要是不来, 我们该怎么办?
3. as long as (=so long as) 表示充分必要条件, 引导语气强烈的条件状语从句时, 意为“只要”。
例如:
I will cooperate as long as I am notified on time. 只要及时告诉我, 我就会合作。
You may use the book so long as you will return it on time. 只要你准时还, 你就可以借这本书。
第2个回答  2018-03-30

条件状语从句的用法是:

1. if 表示正面的条件, 意为“如果”; unless (=if not) 表示负面的条件, 意为“除非, 如果不”。例如: If you ask him, he will help you. 如果你请求他, 他会帮助你。// If you had come a few minutes earlier, you would have met him. 要是你早来几分钟就碰到他了。(本例句属于第8章中介绍过的以虚拟语气表示非真实条件句的情况。) // He is sure to come unless he has some urgent business. 他一定会来, 除非他有急事。

2. in case, on condition that, providing, provided (that), supposing, suppose (that)等词汇意思相近, 指“假如, 假使, 在……条件下”(比if更为书面化)。例如: In case he comes, let me know. 如果他来的话, 告诉我一声。// I shall give you my dictionary on condition that you return it tomorrow. 我将把我的字典给你, 如果你明天要还的话。 // I will go, providing/provided (that) my expenses are paid. 只要我的费用有人付, 我就去。 // Suppose/Supposing (that) he does not come, what shall we do? 他要是不来, 我们该怎么办?

3. as long as (=so long as) 表示充分必要条件, 引导语气强烈的条件状语从句时, 意为“只要”。例如: I will cooperate as long as I am notified on time. 只要及时告诉我, 我就会合作。 // You may use the book so long as you will return it on time. 只要你准时还, 你就可以借这本书。

[考题2] In time of serious accidents, ____ we know some basic things about first aid, we can save lives. (2006重庆)

A. whether B. until C. if D. unless

[答案] C

[解析] 本题应选意为“如果”的if表示假设。

[考题3] I would appreciate it ____ you call back this afternoon for the doctor’s appointment. (2003上海春)

A. until B. if C. when D. that

[答案] B

[解析] 本题应选意为“如果”的if表示假设。

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第3个回答  2016-05-17

  条件状语从句就是用一个句子来作条件状语

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