状语从句讲解

状语从句

定义：

在句中作状语的从句是状语从句，修饰主句中的动词、形容词或副词等。状语从句由从属连词引导，从属连词在句中不充当句子成分，只起连接作用，状语从句放在句首时，要用逗号，放在句尾时不用。

状语从句主要用来修饰主句或主句的谓语。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、比较和方式。

尽管种类较多，但由于状语从句与汉语结构和用法相似，所以理解和掌握它并不难。状语从句的关键是要掌握引导不同状语从句的常用连接词

和特殊的连接词即考点。现分别列举如下:

一、时间状语从句

1.when, while和as的用法

(1)when既可引导一个持续动作，也可引导一个短暂性动作.when强调主从句动作的发生有先后。如：

①When he got there, the classroom had been cleaned.

他到的时候，教室已打扫过了。(主句动作发生在从句动作之前)

②He went to play football when he finished his homework.

做完作业后他就去踢足球了。(主句的动作发生在从句动作之后)

when可作并列连词用，相当于just then，at the time，前一分句多用进行时、be about to或be on the point of doing，表示“正在做..，就在这时发生了另外一件事”或“届时”。如：

①I was reading when he suddenly came in.

②I was about to leave when the telephone rang.

(2)while强调主句动作发生在从句动作所发生的时间段内，从句的动作必须是延续性动词。如：

①Strike iron while it’s still hot.

②Will you please take care of my house while I was away?

在这一情况下，从句的动作一定是延续性动词，如果是非延续动词，要用when。如：

①Will you please take care of my house when I went away?

②当我进来的时侯，他在和别人说话。

While I came in, he was talking with others.

When I came in, he was talking with others.

(3)as引导一个持续性动作，强调主从句的动作同时发生，有“一边..一边..”的意思，也可说明两种正在发展或变化的情况，有“随着..”的意思。如：

①He sang as he walked.他边走边唱。

②As he gets older, he gets more open.

随着年龄的增长，他越发开朗起来。

2.as soon as, the moment, the minute, the second, the instant, no sooner...than, hardly/scarcely...when...，immediately, directly, instantly的用法。

这些从属连词引导的从句都表示从句的动作一发生，主句的动作随即就发生，常译为“一……就……”，The moment she arrives，we can start.

No sooner had we arrived at the station than the train left.

The boy burst into tears immediately he saw his mother.

3.till, until和not...until的用法

(1)在肯定句中，主句谓语动词必须是延续性动词，意为“某动作一直延续到某点才停止”。

You may stay here till/until the rain stops.

你得在这里呆到雨停。

(2)在否定句中，主句谓语动词必须是非延续性动词，从句为肯定式，意为“某动作直到某时间才开始”。He won't go to bed till (until) she returns.

直到她回来他才睡。

(3)not...until句型中的强调和倒装说法。

It was not until you told me that I had any idea of it. (强调句型)

Not until you told me did I have any idea of it. (not until 置于句首，主句要倒装)

Not until he came back did he find his house had been broken into.

4.before和since的用法

(1)连词before表示“还未……就……”，“不到……就……”，“……才……”，“趁还没来得及……”。Before they reached the station, the train had gone.

We hadn't run a mile before he felt tired.

Please write it down before you forget it.

(2)before的句型：It will be＋时间段＋before从句，表示“多久之后才……”。

It will be half a year before I come back.

It won't be long before we meet again.

(3)since的句型：It is/has been＋时间段＋since从句。若从句谓语为非延续性动词，表示“自从……有多久”；若从句的谓语为延续性动词，表示“自从结束/完成……起有多久”。

It is three years since the war broke out.

It is three years since he lived here.

二．地点状语从句

1.地点状语从句可用where, wherever, anywhere, everywhere等引导。地点状语从句可用于主句之前或之后。

You are free to go wherever you like.

Where there is a will, there is a way.有志者，事竟成。

Wherever there is smoke, there is a fire.

无火不生烟(既无风不起浪)。

2.注意区分引导的定语从句与状语从句。

where引导的地点状语从句直接修饰动词，而在定语从句中where作为关系副词要跟在表示地点的先行词后面。

You'd better make a mark where you have any questions.(状语从句)

You'd better make a mark at the place where you have any questions.(定语从句)