赖世雄教你学英语语法
非谓语动词
2-6：分词结构——单句简化法
两句在一起，若无连词相连时，往往第一个从句要简化，变成分词短语。方法如下：
1．被简化的从句中主语与主句的主语相同时，该主语要被删除，若主语不同时则要保留；
2．之后的动词要变成现在分词；
3．若该动词为be动词时，变成现在分词being之后，可予省略，但亦可不予省略，以强调“因为……”的意思。
例：he has nothing to do, he feels bored.(x)
理由：两句无法连接。
改正：化简第一个从句。
第一步：删除相同的主语he；
第二步：其后动词has变成现在分词having，即成：
he has nothing to do, he feels bored.
----having nothing to do, he feels bored.
（无事可做，他觉得无聊。）
例：he was sick of learning, he can away from home.(x)
理由：两句无法连接。
改正：化简第一个从句。
第一步：删除相同的主语he；
第二步：其后动词was变成现在分词being；
第三步：being可予省略。
he was sick of learning, he ran away from home.
----being sick of learning, he ran away from home.
（对学习厌倦了，他离家出走了。）
例：they boy plays around most of the time, his mother is quite mad about it.(x)
理由：两句无法连接。
改正：化简第一个从句。
第一步：由于第一句的主语the boy与第二句的主语his mother不相同，故应予保留；
第二步：其后动词plays变成现在分词playing，即成：
the boy plays around most of the time, his mother...
---- the boy playing around most of the time, his mother...
（这个男孩大部分时间胡混，他母亲对此非常生气。）
使用单句简化法时应注意下列事项：
(l)变成否定分词结构时，not要置于分词前
例：he was not satisfied with the result, he decided to try again.
----being not satisfied with the result, he decided to try again.(x)
----not(being) satisfied with the result, he decided to try again.(o)
（他不满此结果，而决定再试一次。）
(2)句中有助动词do，does，did时，予以删除
例：he didn't intend to see her, he left early.
----not intending to see her, he left early.
（不打算见她，他就提早走了。）
(3)句中有完成时助动词have, has，had，要视为动词而变成现在分词having
例：he had done the work, he felt happy.
-----having done the work, he felt happy.
（做完了这个工作，他觉得很高兴。）
例：i have not seen her for ages, i miss her.
----having not seen her for ages, i miss her.(x)
----not having seen her for ages, i miss her.(o)
（好久没看见她了．我很想她。）
(4)主语不同时，所形成的分词结构，称为独立分词结构
例：john being punctual, i felt happy.
（约翰很守时，我觉得很高兴。）
所谓独立分词结构，就是独立修饰不同主语的分词结构
例：the plan having been carried out, we left relieved.
（计划执行完毕，我们觉得如释重负。）
(5)有时，我们亦可削减第二个从句，变成分词结构。
例：he was reading a book, his wife knitting beside him.
----he was reading a book, and his wife was knitting beside him.
（他在读一本书，而他太太在旁边编织。）
we will go picnicking tomorrow, weather permitting.
----we will go picnicking tomorrow, if weather permits.
（如果天气好，我们明天就去野餐。）