加载中…托福阅读最重要的从句结构：状语从句讲解
(2011-10-28 12:17:05)
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杂谈 |
分类： 考试研究 |
状语从句
1.状语从句定义（Adverb Clauses）
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从属连词+主语+谓语动词（+从句的其他成分） |
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The dog walked to the intersection and waited, just as it had been trained to do. |
主句
状语从句
2. 从属连词（Subordinators）
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时间 |
after |
as soon as |
once |
when |
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as |
before |
since |
whenever |
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as long as |
by the time |
until |
while |
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Children learn their culture from their parents as they listen to family stories. By the time his autobiography was published, Malcolm X had been assassinated. Our brain is busy sorting and storing information while we are sleeping. |
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地点 |
where |
wherever |
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Wherever a bit of soil collects in a sidewalk crack, a seed is likely to germinate. |
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原因 |
as |
because |
now that |
since |
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I will not be answering e-mail next week, as I will be away from my computer. Now that spring has arrived, the days are longer than the nights. |
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目的 |
so that |
so…that |
such…that |
in order that |
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Martin Luther King was such a powerful orator that his speeches continue to inspire people today. |
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对比 |
athough |
even though |
whereas |
despite the fact that |
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even if |
though |
while |
in spite of the fact that |
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Even though it helps some people, doctors disagree on the safety of melatonin. Some students prefer lecture classes, while others like small group discussions. |
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方式 |
as |
as if |
as though |
just as |
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The raccoon rubs and tears its food underwater, as if the food needed washing. |
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条件 |
As long as |
if |
Only if |
Unless |
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Even if |
In case |
Provided that |
Whether or not |
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Dogs are allowed in the city parks only if they are on a leash. Unless fish is properly preserved, it will spoil in just a few days. |
3. 状语从句的位置
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When I was six years old, my grandmother taught me how to bake a pie. My grandmother taught me how to bake a pie when I was six years old. |
当状语从句位于主句后面时，不要求有逗号，但是加上逗号可以用于表示口语中的停顿或主从分句在意义上的区分。逗号经常用于表示对比关系的状语从句中。
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Cats rarely meow at other cats, although they often meow at humans. Schools continue to use intelligence tests, even if they are of limited value. |
4. 副词短语（Adverb Phrases）
当状语从句的主语与主句的主语相同时，状语从句可以被缩简成副词短语。表示时间的状语从句经常被缩简为副词短语。
副词短语中的动词采用现在分词或过去分词形式。因此，副词短语也叫分词短语。
状语从句缩简成副词短语时：
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·
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状语从句 副词短语 |
You should plan your route carefully before you leave home. You should plan your route carefully before leaving home. |
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状语从句 副词短语 |
While he was working as a printer, Benjamin Franklin invented many things. While working as a printer, Benjamin Franklin invented many things. |
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状语从句 副词短语 |
When students were told that tuition would increase, they organized a protest rally. When told that tuition would increase, students organized a protest rally. |
以从属连词as或because引导的状语从句缩简为副词短语时，从属连词被省略。
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状语从句 副词短语 |
As we watched the night sky, we saw seven satellites pass by. Watching the night sky, we saw seven satellites pass by. |
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状语从句 副词短语 |
Because it was once considered a dangerous predator, the wolf has been hunted to near-extinction. Once considered a dangerous predator, the wolf has been hunted to near-extinction. |
下面的句子不能被缩简。主从句的主语都用斜体形式表示。
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When the cat is away, the mice will play. Wherever ornamental grasses are used, the garden will have a finished look. |
5.条件关系状语从句（Conditions）
条件表示一种情况、背景。条件句表达一种导致或不导致某个具体结果的条件。条件句用来表达：
条件句是包含一个从属分句和一个独立分句的复合句。从属分句是表达条件的状语从句。独立分句表达结果，是句子的主句。
与所有从属分句相同，条件从句必须有一个从属连词、一个主语和一个谓语动词。
从属连词+ 主语 + 谓语动词（+从句的其他部分）
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If water flows over loose rock，it will eventually transport most of the rock. |
条件（从句） If water flows over loose rock
因为条件从句是从属分句，所以就不能单独存在，必须与一个作主句的结果分句一起构成完整的句子。
条件从句和结果主句的顺序可以互换，句意不发生改变。当条件从句位于前面时，后面要加逗号。当结果主句位于前面时，逗号可有可无。
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If a submarine's ballast tanks are flooded with water, its weight increases. The weight of a submarine increases if its ballast tanks are flooded with water. |
不同形式的条件句表达不同的时间（过去、现在、将来）以及现实性或真实性的不同程度。各种条件句使用不同种类的动词时态和情态动词。
6.条件关系的从属从句（Subordinators)
在条件句中，条件从句以一个从属连词开头，连接条件从句和结果主句。最常见的从属连词是if, 因此，条件从句有时也被称为if 从句。另外，还有其他一些从属连词可以引导条件从句
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as long as even if |
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As long as the planet keeps spinning, the sun will rise in the east. Professor Wood does not accept late papers, even if you have a good excuse. In case students need enrollment advice, counselors will be available. Banks make a profit provided that they collect more interest than they pay out. Music will always be a part of my life, whether or not I go to music school. |
从属连词unless 表达消极意义。Unless+动词的肯定形式= if+ 动词的否定形式。在下面的两个句子中，条件从句的意思也相同。
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Unless the eggs are kept warm, the young alligators will die. If the eggs are not kept warm, the young alligators will die. |
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Only if you submit it by the deadline will your application be considered. Your application will be considered only if you submit it by the deadline. |
7.现在和将来情况的真实条件句 （Present and Future Real)
如果一个情况是确定的、可能的，那么就是真实的条件。现在情况的真实条件句表达科学事实和普遍真理。
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If+ |
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If the volume of an object expands, the buoyancy of the object increases. If something is vibrating faster than twenty times a second, it is audible to us. If students have eaten breakfast, they are more attentive in class. If it has been raining for several days, the soil becomes saturated. |
在现在情况的真实条件中，有时if 可以用when 替换，句意基本不会有改变。
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Today, if Canadians are traveling cross-country, they usually choose to fly. Today, when Canadians are traveling cross-country, they usually choose to fly. |
将来情况的真实条件句表达在将来肯定、可能发生的情况。将来情况的真实条件句表达科学事实和普遍真理，也用来预测和提建议。
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If + |
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If we hurry, we might catch the bus. If you are studying a foreign language, you have to learn vocabulary and grammar. If the usual treatment has had no effect, the patient may need to consult an allergist. If a project has been making money. The investors should receive some of the profits. |
8.过去情况的真实条件句（Past Real）
过去情况的真实条件句表达普遍真理和过去经常发生的事。
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条件从句
一般过去时
过去进行时 If +
过去完成时
过去完成进行时 |
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In the twelfth century, if you owned land, you were a wealthy person. If Canadians were traveling cross-country before 1900, they had to take the train. Even if a man had been working ten hours, he would receive no dinner break. |
9.现在和将来情况的虚拟条件句（Present and Future Unreal）
如果一个情况是不真实的、不可能的，那么就是虚拟的条件。现在和将来情况的虚拟条件句表达不真实或不可能发生的情况。
在现在和将来情况的虚拟条件句中，条件从句用动词的过去时态，结果主句用情态动词的过去时态+动词原形。主从句中的过去时态表明情况是不真实的、不可知的、不可能的。
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If |
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Present/ Future Unreal |
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If you lived on another planet, the conditions for life might be very different. |
You do not live on another planet; you cannot know about the conditions there. |
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If energy decreased as machines worked, then the machines would eventually slow down. |
Energy does not decrease as machines work; thus, the machine will not slow down. |
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If the trains were running on time, more people might take the train. |
The trains are not running on time; it is unlikely that more people will take the train. |
当be在条件从句中作动词或助动词时，无论是第一人称、第二人称还是第三人称，其他形式都是were。
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If I were a better swimmer, I’d try out for the swim team. If you were going to the same college, I would ask you to be my roommate. If the patient were overweight, he could have a heart attack in the next five years. |
说话者在提出意见或者建议时，通常使用条件从句 if I were you。
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Present/ Future Unreal |
Meaning |
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If I were you, I’d buy the bigger one. |
I suggest that you buy the bigger one. |
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If I were you, I might wait a while before calling him back. |
I advise you to wait a while before calling him back. |
10.过去情况的虚拟条件句（Past Unreal）
过去情况的虚拟条件句表示过去没有发生的情况，表达错误和后悔。
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If |
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Past Unreal |
Meaning |
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If we had hurried, we could have caught bus. |
We did not hurry, and we missed the bus. |
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If their supply ship had arrived on time, the Roanoke colonists might not have perished. |
Their supply ship did not arrive on time, and the colonists perished. |
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If you had been listening, you should have heard what the teacher said. |
You were not listening; you did not hear what the teacher said. |
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