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?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.