关于分词的独立主格结构
在通常情况下，分词作状语时它的逻辑主语应与句子主语一致，若不一致，则应改用其他句型。如：
误：Crossing the road, a car knocked him down.
正：Crossing the road, he was knocked down by a car. 过马路时他被车撞倒了。
正：When he was crossing the road, a car knocked him down. 他过马路时车子把他撞倒了。
解决状语分词的逻辑主语与句子主语不一致的问题，也可在分词前加一个名词或代词，使之成为分词的逻辑主语。由于加在分词前的名词或代词要用主格形式，故称分词的独立主格结构。如：
The job finished, we went home. 工作结束后我们就回家了。
The weather being fine, we went swimming. 天气很好，我们就去游泳了。
He being absent, nothing couldn’t be done. 由于他缺席，什么事也干不成。