- ing 形式作主语时，其逻辑主语对于谈话双方是不言而喻的。

 朗读是很有好处的。Reading aloud is very helpful

 Reading aloud 的逻辑主语是泛指任何人，因而无需表达出来

如果作主语的- ing 形式需要自己的逻辑主语时，一般用物主代词或名词所有格（即名词后加' s ）。

 他父亲生病使他很着急。His father's falling ill worried him greatly

 你来和我们一道工作，对我们是很大的鼓舞。Your coming to work with us will be a great encouragement to us

- ing 形式作表语时，其逻辑主语往往是句子中的主语，但作表语的- ing 形式也可带有自己的逻辑主语。

 我担心的是她天天晚上熬夜熬得太迟。What worries me most is Julia's staying too late every night

 主要的问题是你缺乏大量的练习。The main problem is your not having practiced a lot

- ing 形式作定语时，其逻辑主语就是它修饰的名词。

 一本有意思的书an interesting book  

  a book that interests its readers  

一条奔流的小溪a running stream    

 a stream that is running  

如果- ing 形式的逻辑主语是动作的承受者，就要用- ing 形式的被动式。

 正在北京召开的会议非常重要。The meeting being held in Beijing now is of great importance

逻辑主语 the meeting 和“举行”之间的关系是被动的，所以用 being held

- ing 形式作宾语时，其逻辑主语常是句子中的主语。如要明确动作的执行者，也可以在- ing 形式前加上名词或代词表示逻辑主语。

 我不能想像约翰会在这么多人前面发言。I can't imagine John's giving a speech in front of so many people

 他被某人的敲门声吵醒了。 He was awakened by someone knocking at the door

 老板明白他为什么要离职。The boss understood him his wanting to leave

 他坚持要自己做。He insisted on doing it himself

 他坚持要我做。He insisted on my doing it

 请你把窗子打开好吗？Would you mind opening the window？

 你介意我把窗子打开吗？Would you mind my opening the window？

动词- ing 形式作逻辑主语时，它的逻辑主语就是它前面的宾语。

 我们经常听见她唱这首歌。We often hear her singing this song

 我们经常听见这首歌被人唱。We often hear this song being sung    

   We often hear this song sung

逻辑主语“ this song ”和宾语补足语“唱”的关系是被动，所以用- ing 形式的被动式或- ed 分词。

动词的- ing 形式作状语时，其逻辑主语一般应与句子的主语保持一致。

 走进教室，我发现里面没人。Entering the classroom I found nobody in it  when I entered the classroom I found nobody in it

如- ing 形式表示的动作不是句中主语发出或承受的，那就是误用。这种无依着的- ing 形式，语法上称之为“垂悬分词”。

 从窗户看出去，我们看见一个漂亮的花园。Looking out through the window, we saw a beautiful garden

 我看着晚报的时候，一只狗开始叫起来。I was reading the evening newspaper when a dog started barking

如不能和句子中的主语保持一致，该- ing 形式必须有自己的逻辑主语，通常有名词或代词来担任。

 末班车已经开走了，我们不得不走回家。The last bus having gone, we had to walk home

 天气允许的话，足球赛将在周五举行。Time permitting, the football match will be played on Friday

permitting 的逻辑主语是 time ，而不是 the football match

 generally speaking,    judging from,    considering,    talking of,    supposing,   等，它们的逻辑主语可以和句子的主语不一致。这种- ing 短语可当作一个插入语。

 一般说来，男孩比女孩对科学更感兴趣。Generally speaking, boys are more interested in science than girls

 从他的口音看，他一定来自加拿大。Judging from his accent, he must come from Canada

 考虑到他是多么的穷，我们决定让他免费听音乐会。Considering how poor he was, we decided to let him attend the concert for free

 假使下雨，你会怎么办呢？Supposing it rains, what will you do?