复合句的概念：由一个主句和一个或一个以上的从句构成。
宾语从句一．概念：在句中起到宾语的作用。
二．宾语从句在句中的位置：（1）作动词的宾语：例：I heard that he joined the army. She did not know what had happened.(2) 作形容词的宾语例：I am afraid that I have made a mistake.(3) 作介词的宾语例：Our success depends on how well we can cooperate with one another.三．常见考点分析：（一）．连接词：1.引导陈述句用that（在口语或非正式文体中常常省略）。
2.引导一般疑问句用if或whether。
注意：下列几种情况通常使用whether：（1）．在具有选择意义又有or或or not时，尤其是直接与or not连用时，往往用whether；例：I don’t know whether he will come back or not.（2）．在介词之后用whether；例：They are talking about whether he will win the game.Everything depends on whether you agree with us.3.引导特殊疑问句，只需用原来的特殊疑问词。
（二）. 语序：尤其要注意，宾语从句的语序必须是陈述语序：即主语一定在谓语前面。
尤其要注意whether, if以及wh-(what, why…)疑问词引导的宾语从句的语序。
例：She wants to know whether I like the film.Do you know why winter is colder than summer?（三）. 时态：1.主句中谓语动词是现在或将来时态时，从句中主语不受主句位于时态的影响。
例：She says that she will leave a message on his desk.She says that sh has never been to Beijing.2.当主句谓语动词是过去时态时，从句中的时态一般为表示过去的某种时态（如一般过去时，过去进行时，过去完成时，过去将来时）例：He said there were no classes yesterday afternoon.He said he was going to take care of the baby.3.主句谓语动词是过去时态，宾语从句叙述某一客观真理时，宾语从句用一般现在时。
例：She said that her father is twenty-eight years older than her.The teacher told us that light travels much faster than sound. （四）. 否定转移：当宾语从句表示否定的意义时，若主句主语为第一人称且谓语动词是think / believe / suppose / expect等时，应在主句上加以否定。
例：I don’t think you are right.I don’t believe that he has finished his work.（五）. 注意if或when引导的宾语从句和状语从句的不同。
if / when引导宾语从句时，意思分别为“是否”和“何时”，此时它们的时态根据具体情况而定。
if和when引导状语从句时，意思分别为“如果”和“当……的时候”，此时如果主句是一般将来时，从句部分则用一般现在时。
例：We are not sure if it will snow tomorrow. If it snows, we won’t climb the South Hill.状语从句一．概念和分类：用来修饰主句中的动词，副词和形容词的从句叫状语从句。
分类：时间状语从句，地点状语从句，原因状语从句,目的状语从句，结果状语从句，条件状语从句，方式状语从句，让步状语从句和比较状语从句。
（一）. 时间状语从句：引导时间状语从句的词有：when, as, while, after, before, since, as soon as, ever since, till, until, once, whenever, no sooner …than…, hardly…when…, the moment, every time, each time, next time, directly, immediately, by the time等1．When引导的状语从句和While引导的状语从句的区别：When既可以引导一个持续性动作也可以引导一个短暂性动作。
While只能引导持续性动作。
例：When引导的从句I was thin when I was a child.The film had been on when we arrived.While引导的从句My Mom was cooking while I was doing my homework. 2．Before引导的时间状语从句（1）before引导的从句位于主句之前，一般翻译成在…之前。
例：Before they got to the bus stop, the bus had gone.（2）before引导的从句位于主句之后，一般翻译成…(之后)才。
如果在主句中用将来时，从句要用一般时替代将来时。
例：It will be half a year before I come back.He said that it would be half a year before he came back.3．Until引导的时间状语从句。
（1）延续性动词+until表示直到…为止。
例：You may stay here until the rain stopsHe waited until his friends came.（2）终止性动词或者延续性动词的否定式+until表示直到…才例：He didn’t go to bed until he had finished his work.They didn’t reach the village until it was dark.（3）not until放在句时，主句要用倒装语序例：Not until he graduated did he succeed in obtaining the compound.（直到毕业他才成功获得这种化合物）4．表示一…就…的句型。
As soon as ,once, immediately, the moment，这类从句中经常用一般时态替代将来时态（从句的时态）例：I will tell him as soon as he arrives.Once you study hard, you’ll pass the exam.The moment he comes, I will let you know.5．As的用法主要考点：（1）一边。
一边。
例：He hurried home, looking behind as he went.Tom sings as he works.（2）强调两个动作紧接着发生、例：As he was going out ,it began to rain.（二）地点状语从句由where ,wherever引导。
Where引导定语从句和状语从句的区别：引导定语从句时，从句前应该有一个表示地点的名词作先行词，而状语从句前则没有。
例：1. Go back where you came from.（状语从句）2．Go back to the village where you came from.（定语从句）（三）原因状语从句引导词：because, since, as, now that(既然)，considering that(考虑到)because表示直接原因，语气最强。
Because引导的原因状语从句多放在主句之后。
回答由why提出的问题，只能用because。
As和since语气较弱，一般用来表示明显的原因。
由as和since引导的原因状语从居多放在句首。
例：（1）------Why did you do it?------I did it because I wanted to do it.（2）Since I must die I must do it.（3）As he has no car, he can’t get there easily.（四）目的状语从句引导词：so that(为了，以便)，so(以便)，in order that(以便，这样…就)，in case(以防)目的状语从句的谓语经常含有may, might, can ,could, will, would等情态动词。
例：（1）Speak clearly so that they may understand you. （目的状语从句）（2）Jack is badly ill so that he has to rest （结果状语从句）（五）结果状语从句引导词：so(结果)，so that(结果)，so…that…（如此…以至于）,such…that（如此…以至于）注意so…that…与such…that…的区别So+adj/adv+that 从句such+(a,an)名词+that从句例：（1）The box is so heavy that I can’t carry it.（2）She is so beautiful a girl that all of us like her.（3）She is such a good girl that she can help you.（六）条件状语从句两种情况：1. 祈使句+and/or/or else/otherwise引导的结果句。
例：Hurry up, or else/otherwise you’ll be late.Do that at once, or else I’ll make you do it.引导词：if ,unless(除非，如果不)，so long as(只要), if only(只要)，provided that 或providing(that)(假如)1. 条件状语从句中，如果主句是一般将来时，从句要用一般现在时代替一般将来时。