状语从句一什么是状语从句二状语从句位置三状语从句分类四特殊句式五状语从句常见考点六练一练一什么是状语从句状语从句是行使状语功能的从句，因为其作用相当于副词，它可以用来修饰谓语、定语、状语或整个句子。
状语从句通常由一个连接词或起连接词作用的词组引导。
二状语从句位置比较灵活，有时可以放于句首，有时可以置于句末。
状语从句位于句首时，其后常用逗号与后面的句子隔开。
三状语从句分类让步状语though, although, even though, while whether ，whoever/no matter who ，whatever/ n o m atter w hat ，whenever/ no matterEven t hough y ou s ay s o, I d o n ot believe it.比较状语 than as …as ，the more … the moreThe m ore I s ee him , t he l ess I l ike h im. 方式状语as, as if , as thoughHe t old m e e verything a s i f I w ere h isbest friend.四 特殊句式时间状语中 A:It + b e +时间点+ w hen …… 当某事发生时是什么时候It was 11:00 PM when he came back last night.B:It i s/has b een +时间段 + s ince …… 自从某事发生后已过了多久时间It i s /has b een t wo y ears s ince I e ntered t he t he s enior s chool.C:It + be +时间段 + before …… 在某事发生之前需要多久时间It was 8 years before we finally drove away the Japanese invaders. It m ight b e a l ong t ime b efore C hinese l and o n t he m oon.让步状语从句A: as 引导的让步状语从句， 从句的表语、状语必须前置到句首。
Short as he is, he plays basketball very well.Child as he is, he is knowledgeable. （开头 0 冠词的用法）1 2Much a s I r espect him, I c an n ot a gree w ith h im.B:though 引导的让步状语从句，可以倒装，也可以倒装。
C:其他词引导的都不能倒装。
状语从句的省略现象当主从主语一致，且从句谓语中含有 b e 动词，此时，可以省略从句的主语和 b e 动词A: She always sings while (she is)doing her homework. B: O nce (it i s) s een, i t c an n ever b e f orgotten. C: T hough (it w as) c old, h e s till w ore a s hirt.条件状语从句A:真实条件状语：条件是事实或者在讲话人看来所提出的假设完全可以成为现实 ---> 谓语用陈述语气Ⅰ 从句中的条件是前提，主句中的情境能否实现，取决于条件能否实现。
在这 种条件状语从句，动词不能用将来时态，而用一般现在时代替将来时，用现在完 成时代替将来完成时If you trust before you try, you may repent (后悔) before you die. If we catch the 10 o’clock train, we may get there by lunch time.Ⅱ 主句用祈使句，表示讲话人的请求或提议 If y ou w ish f or p eace, b e p repared f or w ar.Ⅲ 当从句表示到将来某个时刻已经完成或正在进行的动作时，动词可用现在完 成时或现在进行时。
I will return the book on Monday if I have finished it. The p olice won ’t take y our car away if you are s itting in it.3 4Ⅳ表示习惯性动作、科学真理或客观事实，主从句中的动词时态或所使用的情态动词通常一致。
If you pour oil on water, it floats.如果我们把红色和黄色混合起来，我们就得到了橘色。
B:非真实条件状语：指的是所提出的假设实现的可能性极小或与事实相反，谓语动词用虚拟语气。
Ⅰ与现在事实相反：从句谓语动词：v-ed/ were主句谓语动词：would/ could/ might/ should + v.例句：If she worked more slowly, she would not make so many mistakes.I shouldn't go there if I were you.Ⅱ与过去事实相反：从句谓语动词：had done主句谓语动词：would/ c ould/ might/ should + have d one例句：If I had realized t hat he was ill, I should have o ffered to help h im.If anything had happened, he would have let her know.Ⅲ与将来事实相反：从句谓语动词：were + to doshould + dov-ed/ w ere (从句中有表示将来的时间的状语)主句谓语动词：would/ c ould/ might/ should + have d one例句：If the rain were to go on, the crops would be in danger.If I saw/should see/were to see him t omorrow, I would invite h im h ome.Ⅳ当非真实条件状语从句中有s hould, had 或w ere 时，可以省略i f，而把s hould, had 或w ere 提至主语前。
Had I worked hard, I would have surly succeeded.Were s he m y d aughter, I w ouldn’t a llow h er t o s tudy a broad.Ⅴ错综时间条件句：有时非真实条件句谓语动词表示的动作与主句谓语动词表示的动作发生的时间不一致，这叫错综虚拟语气或混合虚拟语气，此时主句与从句的谓语动词的形式根据各自发生的时间来确定。
If I w ere y ou, I w ouldn’t h ave m issed t he c oncert l ast n ight.If you had told m e the news yesterday, I wouldn’t be so worried now.If you h esitated t his m oment, you might s uffer i n future.让步状语从句5A: while 尽管，虽然While w e d on’t a gree, w e c ontinue t o b e f riends.While I understand what you say, I can’t agree with you.B: b e 不管，不论相当于whether or notBe he friend or enemy, the law regards him as a criminal.C: if 即使，虽然If life there was f ull of hardship, it was full of joy and excitement.五状语从句考点时态问题过去完成一般过去过去将来现在完成一般将来将来完成在条件，时间和让步从句中，一般现在时表示一般将来时，用现在完成时表将来完成时，用一般过去时表过去将时。
在since 引导的时间状语从句中，动词一般都用一般过去时，而主句常用现在完成时。
倒装问题（***）A:否定词开头；B:so 加adj. 开头；C: as / though 引导的让步状语从句。
特别注意句式（看见必考倒装）Hardly … when …，No sooner … than …，n/adj，as he is例句：Hardly had he got to the station when the train left.No sooner had he got to the station than the train left.Child a s h e i s, h e c an s peak s even f oreign l anguages.省略问题当状语从句的主语和主句的主语一致时，可以省略状语从句中的主语和系动词be.123A: 连词+过去分词Don’t speak until spoken to.B:连词+现在分词Look out while crossing the street.C: 连词+ 形容词/ 其他常见的有if necessary, if possible, when necessary, if any 等④ 条件状语从句中 unless 和 if not 不可替换的情况如下A: 当i f…not 从句是一个非真实条件句时，unless 不能替换If she weren’t so silly, she would understand.B: unless 强调例外条件I will l eave a t 9, unless y ou want to g o e arlier.C: unless 从句为否定时Don’t ask me to explain unless you really don’t understand.⑤ 引导让步状语从句时，疑问词-ever 与“no matter +疑问词”完全相同，可以互换。
但是疑问词-ever 可以引导名词性从句，“no matter + 疑问词”则不可。
Whatever I suggest/ No matter what I suggest, he always disagrees.I will wait for you however late it is. = I will wait for you no matter how late it is.The child ate whatever we gave him. (不可替换为n o matter what) ***a s if/as though 好像，犹如，有2 种时态6A:表示的情况是事实或具有很大可能性时，从句用陈述语气。