定语从句的省略和状语从句的省略
1.定语从句省略
1）.省略关系代词
只有宾格的关系代词才可以省略（定语从句的宾格关系代词要提前）
I know the man（ whom） you love。
I know （that）the man loves you。
The fish （which） I caught yesterday is still alive。
主格和所有格关系代词不能省略
主格：I like the cat which has blue hair。
所有格：I like the cat whose hair is blue。
2）省略主格关系代词
在某些特殊情况下主格关系代词可以省略
既 如果是“主格关系代词+be+分词”就可以”省略主格关系代词+be“
a）现在分词
The boy who is standing by the door is my brother。
=》The boy standing by the door is my brother。
b）过去分词
I received a letter which was written in English。
=》I received a letter written in English。
c) 关系代词和介词
This is the desk on which I put my bag。
介词+关系代词 不能省略
This is the desk I put my bag on。
如果把介词滞后则关系代词可以省略。
- 状语从句省略
状语从句有一个省略就是把状语从句变成伴随状语从句
由状语从句变成伴随状语从句时候，去掉了引导状语从句的连词或者主语，同时把动词变成现在分词。
Because I felt tired， I went to bed early。=》 Feeling tired， I went to bed early。
When saw the dog， she ran off=》 Seeing the dog， she ran off。
After she finished her homework，she went for a walk。=》 Finishing her homework，she。。。。
Though he is young， he is very smart。
Being young， he is very samrt。
以上动词都是变成现在分词。
a) 主句的主语和从句的主语不一致的情况。
从句和主句的主语不一致的时候，不能省略从句的主语，可以省略连词，动词变Ving。
If it rains tomorrow，I will not go on a picnic。
It raining tomorrow， i will not go on a picnic。
b) 有否词的时候，应该把否定词放在句首。
Because she didnot have money, she couldnot buy it.
Not having money, she couldn't buy it.
c) 句首有being的时候。 在being+ving，省略being
While i was sleeping， i heard a booming sound。
（Being） Sleeping ， I heard a booming sound。
d) 一般而言，当从句与主句不一样时候，单从句的逻辑主语是we，you，they等，也可以省略。例如
If we consider his age， he might be the best person for the job。
按照（a）中首先可以变成：
We considering his age，he might be the best person for the job。
然后按照（d）继续变成：
Considering his age， he might be 。。。。
Judging from his accent，he seems to be an American。
此外还有几个例外的：
Frankly speaking，.......== If I/we speak frankly, .....
Strictly speaking，
Generally speaking，
Supposing it were ture，
Compared with ... （这里用过去分词是因为被动，前面都是主动动作所以是ving）
==If it was compared with ...
==Being compared with... 根据（c）Being得去掉。
==Compared with ...
