关于状语从句的省略问题

关于状语从句的省略问题
在英语学习中我们常见到状语从句省略问题,但并不是所有的状语从句都可采取省略式，可采用省略式的有：
1.when ,while, till, until, once 所引导的时间状语从句。

2.if, unless 所引导的条件状语从句。

3.although, though, even if , even though所引导的让步状语从句。

4.as if, as though所引导的方式状语从句。

5.than 所引导的比较状语从句。

状语从句使用省略的四种情况:
一：当从句的主语和主句的主语一致（从句的谓语常含有系动词be）时，常把从句的主语和系动词一起省略，省略后从句呈现出：Conj+doing /done/adj/adv/to do/n/介短
Eg：
1.You must be careful when (you are )crossing the street.
2.When (he was) asked why he was late, he said he had missed the
train.
3.When /while (he was ) in Paris, he picked up some French.
4.Once ( it is ) seen, it will never be forgotten.
5.Unless ( I am ) invited, I won’t attend his wedding.
6.Though (he was )young/a boy, Tom knows a lot.
7.Even if/though (he is )invited, he won’t go.
8.He must be somewhere around if (he is )not here/in the office.
9.They looked around the room as if /though (they were)looking for
something.
10.H e opened his mouth as if /though (he was) to say something.
11.H e is much taller than (he is) expected.
12.I can’t do it until (I am) told how to.
13.W hen/while (he was) still a boy, he began to support himself.
14.I f (water is )heated to a higher temperature, water will be turned
into steam.
15.T he research is so designed that once_____, nothing can be done
to change it.
A begins
B having began
C beginning
D begun
(D)
16. The 18—storied building ,when ______, will shut out the sun lighting up the rooms in my house.
A completed B. to be completed C. completing D. have completed (A)
17. The flowers will die unless ______every day .
A watered
B watering
C water
D to water (A)
二：当从句的主语和主句的逻辑主语一致时，也可把从句省略为Conj+doing /done/adj/adv/to do/n/介短，此种用法主要是用来描述或
说明某种现象或情况，是“对事不对人”，而第一种情况是就具体的人或事来说明的。

1.While (you are) hiking or rafting, it is important (for you )to think
about safety.
2.There is something important (for you )to remember when (you
are)attending his lecture.
3.To become a top gymnast ,it is important (for you )to start training
when (you are) very young.
4.There are a few simple safety measures (for you ) to follow while (you
are)training.
三：当从句是it is/was+表语时或there be 句型时，常省略it is/was 或there be
1.He made some marks in the article where (it was) necessary .
2.Let’s practise speaking English when and where (it is) possible.
3.I will go to see him for myself if (it is )possible/necessary.
4.Correct the mistakes, if ( there are )any（mistakes）, in the article . 四：当从句的主语和主句的宾语一致时，间或也有这样的省略。

His father told him to be careful when (he was )crossing the street.。