2024年外研版中考英语一轮复习状语从句

状语从句 状语从句的定义:用来修饰主句中的动词,形容词或副词等,充当状语的句子叫状语从句。一般可分为九大类,分别表示时间、地点、原因、目的、结果、条件、让步、比较、方式条件状语从句。 时间状语从句 ①常用引导词:when,as, while , as soon as, before, after, since, till , until, by the time, every time等 ②时态 一、when和while的用法区别 when, while 都有“当……时候”的意思。 1. when引导的时间状语既可以是时间点,也可以是时间段。从句中的动词可以是短暂性动词(非延续性动词/终止性动词),也可以是延续性动词,可与主句中的谓语动词同时发生,也可在其后发生。 e.g. I was doing my homework when my mother got home last night.(got home 是短暂性动作) They called me when I was having dinner.(was having dinner是延续性动作) 2. while引导的时间状语只能是时间段。从句中的动词必须是延续性动词,而且也只能与主句中的谓语动词同时发生或存在。 e.g. While he was riding a bike, a car hit him suddenly.(was riding 是延续性动作) 3. when和while的区别还在于:while 引导的时间状语从句多用进行时态,而 when 引导的时间状语从句多用一般时态。 e.g. My mother was cooking while my father was watching TV. I was doing my homework when my mother came back home yesterday evening. 2、 as的用法 as 从句表示一件事情正在发生,另一件事情也正在进行当中。意为“一边……,一边……;随着……”。as 从句一般用一般过去时,当 as 从句是延续性动词时,as 可与while / when互换使用。 e.g. The students took notes as they listened. I saw Peter as / when / while I was waiting at the bus stop. 三、when、while、as的注意事项 四、before/after引导的时间状语从句 ①before表示主句的动作发生在从句动作之前,如果主句用一般将来时,从句用一般现在时;如果主句用过去完成时,从句用一般过去时。 e.g. He had finished his homework before he went to bed. Before they drive any of the buses, they will have to pass a special test. ②after表示主句的动作发生在从句动作之后。 e.g. I saw them after l arrived. Mother sometimes prepares dinner after I come back home from school. 5、 till和until引导的时间状语从句 两者都表示“直到……才”,主句用延续性动词,主句和从句都用肯定式。 主句用非延续性动词,从句用肯定式,主句用否定式。until较till正式,until引导的时间状语从句可以放在句首。 e.g.Go down the road till you reach the traffic light. Until he was fifty, he didn't marry. 六、since 引导的时间状语从句 since引导的时间状语从句常与现在完成时连用,表示“自从” e.g. I know Bill since he was born. He has studied very hard since he came to our school. 句型:It is/has been +时间段+since从句 e.g. It is / has been two years since the museum opened to the public. 七、as soon as引导的时间状语从句 as soon as引导的时间状语从句,强调两个动作紧接着发生,既可以引导时间状语从句,表示过去,又可以表示将来。 e.g. We'll give him a ring as soon as we get back. He took out hi