要分清动名词和现在分词的概念,两者都是doing形式,但用法不同.
动名词只能作主,表,宾,而现在分词才是作状,定,宾补.
所以,只有现在分词作状语时才涉及到逻辑主语和句子的主语保持一致的问题.动名词一般情况下不涉及这个问题.
The bike is repaired by using a technology.该句中,using a technology 动名词做by 的介宾,整个by doing 这部分作方式状语.因此不涉及逻辑主语的问题.
Reading is a good habit .中动名词reading本身就是主语,它还能跟哪个主语一致呢?
现在分词作状语的例子:
Lying on the grass ,she looked at the stars in the sky .(Lying on the grass 作伴随状语,其逻辑主语为she .)
Crossing the street ,Mike was very careful .(Crossing the street 作时间状语,其逻辑主语为Mike .)
(If) time permitting ,I'll go to see my grandma .(If time permitting 作条件状语,因permitting的动作不是I发出的,因此要加逻辑主语 time )