状语从句是中考词汇和句法部分考查的重点内容之一。在复习状语从句时,主要任务是弄清楚引导各种状语从句的连词的用法。现就主要考查点简述如下:

　　1.引导时间状语从句的连词

　　主要有when, while, as, by the time, before, after, since, till/until, as soon as等。其中when?while和as都可表示"当……时候",但用法有区别:

　　①when意为"在……时;当……时",可表示"点时间"或"段时间",从句谓语可以是终止性动词,也可以是延续性动词。例如:

 　　When I got home, he was having supper.

 　　②as意为"边……边……"或"与……同时",重在表示两个动作同时发生。伴随进行。as从句是终止性动词时,主句通常也必须是终止性动词。例如:

　　They sang as they danced.

　　③while只可表示"段时间",从句谓语只限于延续性动词。例如:

　　While I was sleeping, my father came in.

　　注:从句谓语是持续性动词时,when、while和as可以互换?主?从句谓语都是终止性动词时,when与as可互换?从句谓语表示状态时,通常用while。

　　2.引导原因状语从句的连词

　　原因状语从句一般由because, since, as, for引导?注意as,because,since和for的区别:

　　①如果原因是构成句子的最主要部分,一般用because。because引导的从句一般不放在句子的开头。例如:

　　I missed the train because I got up late.

 　　注:对于以why开头的问句,一般只能用because引导的从句来回答。

　　②如果原因已为人们所知,或不如句子的其余部分重要,就用as或since、since比as稍微正式一些。as和since引导的从句一般放在句子的开头。例如:

 　　As he was not well,I decided to go there without him.

　　Since this method doesn't work, let's try another.

　　③for表示所说的理由是一种补充说明,因此,for引导的从句可以放在括号里,而且for引导的从句一般不放在句子的开头。例如:

　　I decided to stop and have lunch, for I was feeling quite hungry.

　　3.引导结果状语从句的连词

 　　主要有so/such…that…,so that等。

　　1) so...that结构在某种情况下可以与enough to和too...to结构相互转换。例如:

 　　She is so short that she can't reach the buttons of the lift. =She is too short to reach the buttons of the lift.

　　2)so that也可以引导结果状语从句,意为"结果是;以致于"。例如:

　　They missed the bus so that they were late for class.

 　　注:so that也可引导目的状语从句,此时可用to或in order to替换,将其改为简单句。例如:

 　　He got up early so that he could get to school on time. =He got up early to get to school on time. =In order to get to school on time,he got up early.