成人学位英语考试语法辅导及难点释疑：状语从句
状语从句
1.时间状语从句：在时间状语从句中，要注意时态一致，一般情况下主句是将来时的时候，从句要用一般现在时。
As / When I came home, I met an old schoolmate of mine. 我回家的时候遇到了我的一位老同学。
I'll ring you up as soon as I get an answer from him. 我一有他的答复就给你打电话。
Once you see him, you will never forget him. 你一旦见过他，就不会忘了他的。
Whenever we met with difficulties, they came to help us. 每当我们遇上困难的时候，他们就来帮我们。
Each time he came to town he would visit our school. 他每次进城，总要来看看我们的学校。
Every time I went to his house, he was out. 我每次去他家，他都出去了。
It is just a week since we arrived here.(It is /was… since…是常用句型)
我们到这儿刚刚一星期。(主句的动作或状态持续时间较短，不能用ever since)
Things went well until/till one night an accident happened. 事情一切正常，直到有一天晚上发生了意外。
2.地点状语从句
地点状语从句是由where(在……的地方)，wherever(无论哪里)引导的：
Wuhan lies where the Yangtze and the Han River meet. 武汉位于长江和汉水汇合处。
Where there is a will, there is a way. 有志者，事竟成。
You'd better make a mark where you have any questions.(这里where引导的从句不是定语从句)哪儿有问题，你最好在哪儿做个记号。
He would keep in touch with us wherever he was. 他无论在什么地方，总与我们保持联系。
3.原因状语从句
表示原因的状语从句可以由as(由于)，because(因为)，since(既然)，now (that)(既然)，considering that(顾及到)，seeing that(由于)等连词引导：
I do it because I like it. 因为我喜欢我才干。(because不能与so连用)
Seeing (that) quite a few people were absent, we decided to put the meeting off. 由于好些人都没到会，我们决定延期开会。
Now that/Since you are all here, let's try and reach a decision. 既然大家都来了，咱们就设法做出一个决定吧。
As she was ill, she didn't come to the party. 由于病了，她没来参加晚会。
Considering that they are just beginners, they are doing quite a good job. 考虑到他们才刚刚学做，他们干得算很不错的了。
4.目的状语从句
引导目的状语从句的主要连词有：that, so that(以便), in order that(为了), for fear that(以便), in case(万一)等，从句中常常使用一些情态动词，如：can, could, may, might, should等。如：
Let's take the front seats (so) that we may see more clearly.
我们坐前排吧，这样我们看得更清楚些。
School was closed early in order that the children might go home ahead of the storm. 早点儿放学是为了让孩子们在暴风雨到来之前回家。
He took the name down for fear that he should forget it. 他把名字写下省得忘了。
(该从句中一般用情态动词should+动词原形，或省略should)
Better take more clothes in case the weather is cold. 最好多带些衣服以防天气会冷。
5.结果状语从句
引导结果状语从句的连词有：so that(从句中不带情态动词)，so…that(如此……以致……)，such…that(如此……以致……)等。
He didn't plan his time well, so that/so he didn’t finish the work in time. 他没把时间计划好，结果没按时完成这项工作。
We left in such a hurry that we forgot to lock the door. 我们走得匆忙，把门都忘了锁了。(such是形容词，后接名词)
The village is so small that it cannot be shown in the map. 这村子太小，所以这地图上没有。(so是副词，后接形容词或副词)
Jenny is such a clever girl that all the teachers like her very much = Jenny is so clever a girl that…Jenny是如此聪明的女孩，以至老师们都非常喜欢她。
但是，当名词前有many, much, few, little(少)修饰时，要用so，不能用such。例如：
I have had so many falls that I am black and blue all over. 我摔了许多跤，以至于浑身青一块，紫一块。
He has so few friends that he often feels lonely. 他朋友很少，所以经常感到孤独。
I had so little money then that I couldn't afford a little present. 我当时囊中羞涩，连一份小小礼物都买不起。
6.条件状语从句
表示条件的状语从句可以由if(如果)，unless(除非)，in case(万一)，so /as long as(只要)，as/ so far as(就……而言)，on condition that(条件是……)，suppose(假设)，supposing(假设)(仅用在问句中)等词或词组引导。一般情况下当主句是将来时的时候，从句要用一般现在时。
As/So long as we don't lose heart, we'll find a way to overcome the difficulty. 只要我们不灰心，我们就能找到克服困难的方法。
Send us a message in case you have any difficulty. 万一有什么困难，请给我们一个信。
If you leave at 6 o'clock tomorrow morning, you'd better get to bed now. 如果你明早6点钟走，你最好现在就上床。
We'll let you use the room on condition that you keep it clean and tidy. 只要你能保持整洁，我们可以让你使用这个房间。
As/So far as I know, he is an expert on DNA. 据我所知，他是一个DNA专家。
He'll accept the job unless the salary is too low/ if the salary is not too low. 他会接受这项工作的，除非薪水太少/如果薪水不太少的话。
Suppose/Supposing we can't get enough food, what shall we do? 假设我们弄不到足够的食物，那我们怎么办?
7.方式状语从句
方式状语从句常由as(与……一样)， as if(仿佛)， as though(仿佛)等词引导：
Do in Rome as the Romans do.入乡随俗。Leave things as they are.让一切顺其自然。
She stood at the door as if (=as though) she were waiting for someone.
她站在门口，仿佛在等人似的。(由as if或 as though引导的从句中可用虚拟语气)
8.比较状语从句
比较状语从句常由than(比)， as(与……一样)等词引导：
It rains more often in Shanghai than in Beijing.上海下的雨比北京的多。
Our country is as big as the whole of Europe.我们的国家同整个欧洲一样大。
The result was not as/so good as I had expected.结果不如我预料的那么好。
The busier he is， the happier he feels.(常见句型)他越忙越开心。
9.让步状语从句
让步状语从句由although(尽管)，though(尽管)，however(无论怎样)，whatever(无论什么)，whoever(无论谁)，whomever(无论谁)，whichever(无论哪个)，whenever(无论何时)，wherever(无论哪里)，whether(是否)，no matter (who, what, where, when, etc)(无论……)，even if(即使)，even though(即使)等词引导。如：
We won't be discouraged even if (=even though) we fail ten times. 我们就是失败十次也不泄气。
It was an exciting game, though / although no goals were scored. 那是一场精彩的球赛，尽管一个球都没进。(though， although不能与 but连用)
Whether you believe it or not, it's true. 不管你信不信，这是真的。
However (=No matter how) expensive it may be, I'll take it. 无论它有多贵，我也要买下它。
Don't let them in, whoever(=no matter who) they are.不管他们是谁，别让他们进来。
No matter what I say or how I say it, he always thinks I'm wrong. 无论我说什么或怎么说，他总认为是我错。
连词as也可以引导让步状语从句，但从句中要用特殊语序。如：
Young as he is, he knows a lot=Though he is young 或Young though he is, he… 他虽然年轻，但懂得很多。
难点释疑：
1.当hardly, scarcely, no sooner位于引起的句子的开头时，常用倒装语序。
No sooner had he arrived there than he fell ill.
Hardly had he finished when someone rose to refute his points.
Scarcely had she fallen asleep when a knock at the door awakened her. 这三组关联词引起的句子中，前面常用过去完成时，后面用一般过去时。
2.if和unless的用法
一般情况下，unless相当于if…not，可以互换。如：
I won't let you in unless you show me your pass = I won't let you in if you don't show me your pass. 如果你不出示通行证，我就不让你进来。
