状语从句一、时间状语从句1、引导词：when, while, as（1）when的用法①既可以引导一个延续性动作，也可以引导短暂性动作可用于主从句动作同时发生，也可用于从句动作先于主句动作②可做并列连词，意为“那时，这时，突然”，相当于at this/that timeI was reading a novel when someone knocked at the door.还可以表示原因，意为“既然”；表条件，相当于ifHow can you hope to get mercy when you don’t show mercy on others?(when=if)③be doing when + did突然，意想不到的结果be about to do...when...我刚准备干...突然...had just done...when...我刚刚做完...突然...（2）while的用法①while引导必须是持续性的，侧重主从句动作同时发生Please don’t talk so loud while others are working.②可做并列连词，意为“而，却”，表对比While Tom was studing, Ted was playing computer games.③引导让步状语从句，意为“虽然”，相当于though, althoughWhile I accept that he is not perfect, I do actually like the person.（3）as的用法as引导延续性动作，主从句主语是相同的，多表示主从句动作同时发生意为“一边......一边......；随着”Jane sings as she works.2、引导词：as soon as, immediately, instantly, directly, the moment, the minute, once, no sooner... than..., hardly/scarecely...when...都意为“一......就......”，从句中用一般现在时代替将来时Once you remember it, you will never forget it.注意：no sooner......than......hardly............when......scarecely........when......↓↓用过去完成时一般过去时I had hardly got home when it began to rain.若把no sooner, hardly, scarecely放在句首，其后的句子要倒装No sooner had we arrived at the station than the train left.3、引导词：till, until, not...until...（1）肯定句：意为“某动作一直持续到某时间点才停止”“一直到......”Please wait until I come back.（2）否定句：意为“某动作一直到时间某点才开始”“直到......才......”He won’t go to bed till/until she returns.（3）till不可用于句首，而until可以Until you told me I had no idea of it.（4）not...until...句式的强调与倒装用法强调句：It be + not until + that + 主语+ 动词过去式It was not until you told me that I had any idea of it.4、引导词：before, since（1）若表达“还未......就......”“不到......就”“......才......”“趁......还没来得及”要用before We hadn’t run a mile before he felt tired.（2）It will be + 一段时间+ before sb. do sth. “多久之后才......”It will be half a year before I come back. It was (not)...before...“不久......就......”（3）since引导从句的谓语动词一般过去时，主句现在完成时/现在完成进行时She has been working in this factory since she left school.（4）在It is + 一段时间+ since 从句的句型中，时间计算一律从since从句的动作完成或结束状态时算It is three years since she was in our class.It was 3 years since he had lived there.他不住这儿已经3年了。

二、地点状语从句引导词：where, wherever(在任何地方)=no matter where(无论何处)The photo of mine was taken where stood the famous high tower.Wherever you go, you can see new facrories and stores.三、原因状语从句1、引导词：because, as(由于), since(既然), now that, seeing that, considering thatAs the weather was fine, I opened all the windows.2、for引导的并列句也可表原因，不可放在句首“因为......其原因是......”It must have rained last night, for the ground is still wet.3、介词短语because of, owing to, due to, thanks to等也表示原因Thanks to the bad weather, they put off the sports meet.四、条件状语从句引导词：if, unless(if...not), as long as, so long as(只要), in case(万一)As long as you understand the rule, you will have no futher difficulty.五、方式状语从句引导词：as, as if, as though(好像), just as, as...so...(正如，就像)Do just as you like.As A is to B, so C is to D. 正如......一样六、让步状语从句引导词：though, although, even if, even though, whether...or...(不管...还是...), whoever, whichever, however, whatever, whenever, no matter who, no matter which, no matter how, as(尽管), while(=though)Child as he is, he can do the work well.Though he is young, he knows...七、目的主语从句引导词：so that, in order that, for fear that(以免), in case, lest(免得，以防，唯恐)Come round to the windows so that I can see you.in order that 和so that的用法，从句中常有情态动词八、结果状语从句引导词：so that, so...that, such...that(如此...以至于), as a result(表结果), as a result of(表原因)用法如下：so + 形容词/副词+ that从句so + 形容词+ a/an + 可数名词单数+ that从句so + many/much/little/few + 名词+ that从句such + a/an + 形容词+ 可数名词单数+ that从句such + 形容词+ 可数名词复数/不可数名词+ that从句such + a lot of/lots of + 名词+ that从句It is such fine weather that we all want to go to the park.He earned so little money that he couldn’t support his family.当so和such置于句首时，主句要倒装So clever was he a student that he was able to work out all the difficult problems.九、比较状语从句引导词：as...as..., more...than..., than, less...than..., the more...the more..., the same...as, such...asHis name is the same as his father’s (name).Tom is as good a student as Jack. =Tom is such a good student as Jack.。