1、*1*语法复习专题（13）Unit13 状语从句一、考点聚焦1、时间状语从句（1）as、when 、while 用法一览表。类别 作 用 例 句asas 表示“当的时候” ，往往和 when/ while 通用，但它着重强调主句与从句的动作或事情同时或几乎同时发生。She came up as I was cooking.(同时 )The runners started as the gun went off.(几乎同时)when(at or during the time that )既可以表示在某一点的时候，又可表示在某一段时间内，主句与从句的动作或事情可以同时发生也可以先后发生。It w
2、as raining when we arrived.(指时间点)When we were at school, we went to the library every day.(在一段时间内)whilewhile 意思是 “当 的时候”或“在某一段时间里” 。主句中的动作或事情在从句中的动作或事情的进展过程中发生，从句中的动词一般要用延续性动词。在when 表示 a period of time 时，两者可以互换。Please dont talk so loud while others are working.He fell asleep while/when reading. Stri
3、ke while the iron is hot.(用 as 或 when 不可，这里的 while 意思是 “趁”)（2）引导时间状语从句的连接词除上述外还有：till, not until , until, before, sinceDont get off the bus until it has stopped.He waited for his father until(till)it was twelve oclock.It will be five years before he returns from England.hardly / scarcely when, no so
4、oner than, as soon as once表示“一就”As soon as I have finished it , Ill give yu a call.Once you show any fear, he will attack you.We had hardly got / Hardly had we got into the country when *2*itbegan to rain.No sooner had he arrived / He had no sooner arrived than she started complaining.directly, imme
5、diately, the moment, the minute that 一就He made for the door directly he heard the knock.each time, every time, by the timeEach time he came to my city, he would call on me.注意：表示未来情况，主句用将来时，从句用现在时。2、让步状语从句（1）although 与 though 可以引导让步状语从句，不能与 but 连用，但可以与 yet 连用。Although they are poor,(yet)they are warm
6、-hearted.（2）even if 或 even though 引导让步状语从句，表示“即使” ，“纵然” ，用来使人注意下文所强调内容的性质。Ill get there even if(though)I have to sell my house to get enough money to go by air.（3）no matter 后接上 who、what、where、how 等疑问词，也可以在这类疑问词后面加上 ever 构成whoever、whatever、wherever、however 等。Dont trust him, no matter what / whatever
7、he says.Whoever breaks the law will be published.No matter how hard the work is, youd better try to do it well.（4）as 也可以引导让步状语从句。要用倒装。Child as(though)he is, he knows a lot.Much as I like it, I wont buy.Try as he would, he couldnt lift the heavy box.3、原因状语从句：because, for, as, since, now that（1）表示不知道的
8、原因时用 because,即说话人认为听话人不知道，因此 because 从句是全句最重要的部分，通常它被置于主句之后。You want to know why Im leaving? Im leaving because Im full.for 虽然表示不知道的原因，但其语气较 because 要弱得多，是可说*3*可不说的话，它只能置于主句之后，这时，for 是并列连词。如果不是因果关系，而是对前面主句的内容加以解释或推断时，只能用 for。如：Its morning now, for the birds are singing.（很显然，鸟叫不可能是“现在已是早上”的原因。 ）（2）表示
9、已经知道的原因时用 as 或 since,即某种原因在说话人看来已经很明显，或已为听话人所熟悉，因此它是句中不很重要的部分。since 要比 as 正式一些，它们通常被置于语句之前，但有时却相反。Seeing all of the children already seated, he said,“Since everyone is here, lets start.”(3)下列情况下只能使用 because:在回答 why 的问句时；在用于强调句型时；被 not 所否定时。4、地点状语从句：where, whereverMake a mark wherever you have any qu
10、estions.We will go where the Party directs us.5、目的状语从句：that, so that, in order that注意：目的状语从句的谓语动词常与情态动词连用，否则可能是结果状语从句。不可置于句首。6、结果状语从句：that, so that, so that, such that 注意：so + 形容词/副词 + that 从句；such + 名词 + that 从句。7、方式状语从句：as, as if(though)Ill do as I am told to.It looks as if it is going to rain.8、比
11、较状语从句：than, as9、条件状语从句：if, unless, so (as) long as, in case, once, a far as, on condition that.注意 if 与 unless 的区别：不能用 and 连接两个 unless 从句，即不能有 unless ,and unless 。但 if not and if not 却不受此限。You wont lose your weight unless you eat less and unless you exercise more.()但可以说 unless you eat less and exerci
12、se more.10、注意状语从句中从句的省略现象*4*（1）连接词 + 过去分词Dont speak until spoken to.Pressure can be incrased when needed.Unless repaired, the washing machine is no use.（2）连词 + 现在分词Look out while crossing the street.（3）连词 + 形容词/其他常见的有 it necessary、if possible、when necessary、if any等。二、精典名题导解选择填空1. I dont think Ill ne
13、ed any money but Ill bring some _.(NMET 2000)A.as last B.in case C.once again D.in time解析：答案为 B。句意为“带些钱以防万一 ”，只能选择 in case。引导的条件状语从句，后面省略了 I should need it。2. The WTO cant live up to its name _ it doesnt include a country that is home to one fifth of mankind.（NMET 2000）A.as long as B.while C.if D.even though解析：答案为 C。本题考查状语从句的用法。句意为 “假如世贸组织不包括占世界人口五分之一的中国的话，那它就名不副实” 。as long as 语气过于强烈，while 和 even though 不符合句意。3、Someone called me up in the middle of the night, but they hung up_I could answer the phone.(NMET 2000)A.as B.since C.before D.until解析：答案为 C。题意为：半夜里有人打来电话，我没来得及就挂了。but 暗示在接话前就挂了。
