现在分词作定语时，它所修饰的名词通常就是现在分词的逻辑主语，并且通常可转换成一个定语从句;而动名词作定语表示的是被修饰名词的作用、用途等。
比较：
a moving truck 正在移动的汽车(moving为现在分词，与truck有主谓关系)
a moving truck 搬家汽车(moving为动名词，说明truck的用途)
a hunting dog 正在猎物的狗(hunting为现在分词，与dog有主谓关系)
a hunting dog 猎狗(hunting为动名词，说明dog的用途)
分词用作状语
分词作状语可以表示多种关系：
(1) 表时间：
Seeing the cat, the mouse ran off. 见到猫，老鼠就跑了。
The work finished, he went home. 工作做完后，他就回家了。
(2) 表原因：
Being very weak, she couldn’t move. 她由于身体虚弱而不能行动。
His car broken down, he had to walk. 他的车坏了，所以只好走路。
Much discouraged，she moved on to London. 她很沮丧，搬到了伦敦。
(3) 表条件：
United, we stand; divided, we fall. 团结则存，分裂则亡。
Given more time, we could have done it better. 如果多给点时间，我们可以做得更好。
Working hard, you will succeed. 如果努力工作，你就可以成功。
Adding them all up, we can find the answer. 如果把它们加起来，我们就可以得到答案。
(4) 表让步：
Although living miles away, he attended the course. 虽然住在几英里以外，他仍去上课。
Defeated, he remained a popular boxer. 虽然被击败了，他仍是一个受欢迎的拳击手。
(5) 表方式：
He earns a living driving a truck. 他靠开卡车谋生。
I'm returning you letter as requested. 我按要求给你退信。
(6) 表伴随：
He sat in the chair reading newspapers. 他坐在椅子上看报。
Don't you sit there doing nothing. 别什么也不干坐在那里。
He came in, followed by his wife. 他走了进来，后面跟着他的妻子。
(7) 表结果：
He fired, killing one of the passers-by. 他开枪了，打死了一个过路人。
He died, leaving his wife with five children. 他死了，留下他妻子和五个孩子。
It rained and rained, vehicles bogged and bridges washed out. 雨不停地下，车辆陷入泥沼，桥梁被水冲去。
