状语从句与分词作状语的转换

状语从句与分词作状语的转换
时间、原因等状语从句可以转换成分词作状语，但这种转换是有条件的，也有一定的规律可循。

一、基本规则，也是最重要的规则是：从句的主语与主句的主语必须一致，变从句而主句不变。

如：
They did not go to the Summer Palace because they had a lot of work to do．
由于从句的主语与主句的主语都是they，可以把从句中because和they去掉，把had变成having，即成现在分词短语作原因状语：
Having a lot of work to do，they did not go to the Summer Palace．
二、从句如果表示主动、完成，进行的动作，则转换成现在分词；如果表示被动，则转换成过去分词。

1．When he heard a cry for help，he rushed out．
从句中，he was与heard是主动关系，表示“他听见”。

则可变成现在分词作时间状语。

Hearing a cry for help，he rushed out．
2．The boy Cater went up to his teacher and said“sorry”because he was great-ly touched by his words．
从句中，he was touched是被动关系，是“孩子被深深地触动了”，则变成过去分词作原因状语。

Greatly touched by his teacher's words，the boy laterwent up to him and said“sorry”．
三、如果从句的主语与主句的主语不一致，该怎么办？请看下例：
1．As the heroes' deeds moved them deeply，they decided to study even harder．
句中，主句的主语是they，而从句主语是the heroes'deeds，主语不一致，这时可以把从句变换一下句型，变成被动语态。

即成As
they were deeplymoved by the heroes'deeds．从句的主语与主句的主语都是they，就可转换成：Deeply moved by the heroes'deeds，they decided to study even harder．
下列的句子中主语也是不同的。

2．The professor came into the lab；a group of students followed him．
这是两个简单句，如果中间加个and也可看成并列句。

但主语不同，可以先把第二句变成：He was followed by a group of students．全句就转换成：
Followed by a group of students，the professor came into the lab．
四、如果看不出有从句，该怎么办？请看下例：
He recognized the man who had been his classmate ten years before，so he wentover to say hello to him．
这句中，看不出有从句。

so是并列连词，表示“因此，于是”等意思。

这样一来，前面那一句就有表示原因的意味。

这一句可以改写为：
Because he recognized the man who had been his classmate ten years before，he went over to say hello to him．变成一个原因状语从句，即可转换成现在分词作原因状语。

Recognizing the man…
许多有and或没有and的并列句，只要主语一致，往往可能换成分词作伴随状语。

如：
The students went home from school；they talked and laughed．可转换成：
Talking and laughing，the students went home from school．
五、如何判断要不要有一个Being？如：
As he was very old，he had to give up his teaching．
可转换成：Being very old，he had to give up his teaching．再看下例：
As he was moved by the story，he decided to learn from the heroes．
则转换成：Moved by the story，he decided to learn from the heroes．而不是Being moved…
为什么呢？原来前面的那一句的was是系动词（link verb），后面跟的是表语（形容词或名词）。

又如：As he was an engineer，he knew exactly what to do．
an engineer．是名词作表语，即可转换成：
Being an engineer，he knew exactly what to do．而后面那一句的被动语态was是助动词，只需过去分词就可以了。

但英语中有许多过去分词已经形容词化了，如be interested in（对……感兴趣），be excited（因……激动）等，往往表示一个状语，则仍需加Being。

如：
As he was filled with new ideas，the young man invented many kinds of mod-ern machines．
如果把be filled with理解为be full of是一种状态，则可转换成being filledwith…，如果把be filled理解为单纯的被动，则转换成Filled with new ideas…二者都可。

但下句：As the room was filled with many people，it became hotter andhotter．
这是纯粹表示被动的，则只能转换成：
Filled with many people，the room…
六、有时，还要考虑到时态的变化。

如：
The children went out to play after they had finished their homework．
由于有时间的先后，从句的动作发生在前，主句的动作发生在后，因此，要用现在分词的完成式作时间状语。

即：
Having finished their homework，the children went out to play．
如果是表示一个既完成又被动的动作，可以用现在分词的完成被动式。

如：
As she had been given such a good chance，how could she let it slip away？
可转换成：Having been given such a good
chance…但往往简化成过去分词作原因状语Given such a good chance，…
因为过去分词本身就表示完成、被动的，但似乎用现在分词的完成被动式更正式也更强调些。