子的主语就是分词的逻辑主语。

　　Having been shown around the factory, they were very happy．(现在分词的被动式)

　　被领着参观了工厂后，他们很高兴。

　　Having finished his homework, he went to bed．(现在分词的主动式)

　　完成了作业后，他上床睡觉。

　　即时演练3

　　3－1．用所给动词的适当形式填空

　　①Being_talked (talk) to, you should look into the eyes of the person．

　　②Having_been_told (tell) for several times, he still couldn't understand the rules．

　　③Hearing (hear) the bad news, she didn't know what to do．

　　3－2．单句改错

　　④(重庆高考改编)Being asked to work overtime that evening, I missed a wonderful film．

　　 Being_asked→Having_been_asked

　　3．动词­ing 形式的否定式：not ＋v．­ing; not having ＋ v．­ed

　　Not knowing this, he didn't come．

　　他不知道这件事，所以没来。

　　Not having made full preparations, we put off the sports meeting．

　　因为没有做好充分的准备，我们把运动会延期了。

　　4．独立主格

　　动词­ing形式作状语，有时它也可以有自己独立的主语，这种结构称为独立主格结构，通常用来表示伴随的动作或情况，也可以表示时间、原因或条件。

　　All the students having sat down, the lecture began．

　　所有学生坐好之后，讲座开始了。

　　The new year coming, we were happy．

　　新年来了，我们很高兴。

　　The regulation permitting, I will go with you．

　　制度允许的话，我就和你去。

　　即时演练4

　　4－1．用现在分词的独立主格结构改写下列句子

　　①If weather permits, we shall go there on foot．

　　→Weather permitting,_we shall go there on foot．

　　②After Mary came back, they discussed it together．

　　→Mary coming back,_they discussed it together．

　　4－2．完成句子

　　③(江苏高考改编)The_lecture_having_been_given (讲座结束后), a lively question­and­answer session followed．

　　④Spring_coming_on (春天来了), the trees turned green．

　　5．现在分词作评注性状语

　　有些现在分词在句中没有逻辑主语，它们往往作为句子的评注性状语来修饰整个句子，表明说话者的态度、观点等。例如：generally speaking "一般来说"，judging by/from ．．．"从......判断"，taking everything into consideration "从全盘考虑"。

　　Judging from his behaviour, he must be mad．

　　从他的行为来判断，他一定是疯了。

　　Generally speaking, girls are more interested in literature than boys．

　　一般来说，女孩比男孩对文学更感兴趣。