状语从句
定义：英语中，修饰动词、形容词、副词等的句子成分叫做状语。状语的功用是说明时间、地点、原因、条件、方式、让步、目的、结果、比较状况的。 例：
When the film ended, they went home.（时间） You can go where you want to go.（地点）
The ground is wet because it rained last night.（原因） I will go if my wife is invited too.（条件） Think as I think.（方式）
Although he is rich, he is not happy.（让步） He works hard in order to study well.（目的） The box is so heavy that nobody can move it.（结果） I know him better than you do.（比较）
考点：从句意出发正确选出合适的连词；从语境出发，正确判断主句从句的时态。 1. 时间状语从句
引导时间状语从句的连词有：when，as，while，before，after，till（until），since， as soon as等。 (1) when, while, as when: 1.当??的时候”
When the film ended, they went back.
2.含有“就在那时”之意 was doing something…when was about to do…when
while:“当??的时候”，后加持续性的动作，强调相对 I like listening to music while I am doing my homework. Please don’t talk so loud while others are working.
as: “一边……一边……”“随着……” 强调交替进行，同时发生 She sang as she walked home all the way. As she grew older, she became more beautiful.
(04北京春) We were swimming in the lake ______ suddenly the storm started. A. when
B. while
C. as D. before
(全国) Mary made coffee her guests were finishing their meal. A. so that B. after
C. while D. as (2) before, after
before: 1. “在……之前”，主句的动作在从句之前。
2. “…才…”，“不到…就”，“还没（来得及）…就”. It won’t be long before he is ready for his new job. It will be 6 years before this medicine is put into use. We hadn’t run a mile before he felt tired.
We had sailed four days and four nights before we saw land. after : “在……之后”，主句的动作在从句之后。 After you use plastic bags, you mustn’t throw them about. (06四川)－Why didn’t you tell him about the meeting? －He rushed out of the room ____ I could say a word. A. before B. until
C. when
D. after
(09年北京) He made a mistake, but then he corrected the situation ______ it got worse. A. until
B. when
C. before D. as
(3) till, until, since
till不可以置于句首，而until可以
until 用于肯定句, 主句谓语动词必须是延续性动词 “一直到” not…until 直到 …才，且not until置于句首时，主句倒装 He lived with his parents until he graduated from college. I’ll wait until it comes out on DVD.
not…until… (主句短暂性动词) “直到…才”
I didn’t leave until he came back. (Not until he came back, did I leave.) since 自……以来，强调动作发生到现在
it is (has been)…..+ since +一般过去时 It is five years since I began to learn English.
（08年陕西7）Not until the motorbike looked almost new ____ repairing and cleaning it.
A. he stopped B. did he stop C. stopped he D. he did stop
（09年四川16 ）Not until I came home last night ________ to bed. A. Mum did go B. did Mum go C. went Mum D. Mum went 2. 让步状语从句
让步状语从句由although（though），as，even if，．however, whether…or, whatever，no matter＋when／how／what／who／where等词引导。 一、 though和although
although是较正式语体，语气比（even）though强，且一般用在句首。（even）though比较通俗，较常用。下列情况只能用though： 1. 在部分倒装的从句中，如：
Young though he was，he was burdened with a big family.
2. 在as though，even though等短语中though不能用although代替。值得注意的是，不管 though还是although，都不能与but连用。 二、 由as引导的让步状语从句
由as连词引导的让步从句是一种部分倒装句，其结构通常是：adj.(adv, n 或v)＋as＋主语＋谓语＋其他成分＋（主句）。注意，名词前不用冠词。如： Tall as he is，he cannot reach the top shelf．（前面是形容词） Fast as he ran, he missed the first bus．（前面是副词） Hero as she is，she is modest. （前面是名词） Try as I might，I couldn't lift the stone．〔前面是动词原形〕 上述句子中的as都可以用though代替。
____, the idea of having to work under a woman defeated him. A. Wanting the job very much B. Although wanting the job badly
C. Though he wanted the job very much D. He wanted the job badly
Food shortage will long be a world problem _______much has been done to supply enough for everyone.
A. although B. no matter C. since D. before 3. 条件状语从句
如果主句是将来时，条件状语从句用一般现在时表示 If you touch an English person, you should say “sorry”. You’ll fail the exam unless you study hard. In case ：万一；倘使
In case you need something, please don't hesitate to let me know.
As / so long as we don’t lose heart, we’ll find a way to overcome the difficulty. (只要)
You can borrow the car provided (that) you can get it back to me before 10 o’clock.（如果）
You can be allowed to play the game on condition that you finish your homework first.（条件是）
Supposing/ suppose (that) you fail a second time ,don’t get disappointed, but try again. (假设如果)
I told him he would succeed only if he tried hard. （唯一的条件是）
If only they were here now, we would be able to celebrate their wedding anniversary. （要是…该多好）
The little boy won’t go to sleep his mother tells him a story.（2010全国）
A. or B. unless C. but D. whether _____ I can see, there is only one possible way to keep away from the danger. （04北京春季）
A. Because B. As far as C. Even if
I always take something to read when I go to the doctor’s ________ I have to
