一、句子主语是表示事物的名词。现在分词在句中作状语，其逻辑主语是句子被动结果的行为执行者。例如：

　　Standing on the top of the hill, the whole town can be seen clearly. 站在山顶上，这个小镇看得清清楚楚。（see 的执行者就是standing 的逻辑主语。）

　　二、句子主语是用作形式主语的代词it，分词的逻辑主语常常蕴含在it 句中。例如：

　　Finding all his things, it will take him four hours.  要找到他所有的东西得花几个小时的时间。（finding 的逻辑主语就是句中him 所指的人。）

　　Buying all the furniture, it will cost us a lot of money.买好所有的家具要花费我们许多钱。（buying 的逻辑主语就是us 所指的人。）

　　三、有些现在分词已经转化为“评注性状语”，说话者本人就是该分词动作的逻辑主语。常见的有：generally (frankly, honestly, partly, exactly, strictly, personally, roughly, broadly) speaking, speaking for oneself, judging from /by, talking/speaking of, beginning with..., taking everything into consideration（对……加以考虑）等。例如：

　　Broadly speaking, dogs are more faithful to man than cats. 概括地讲，狗对人要比猫对人忠诚得多。

　　Taking everything into consideration, he ought to be given another chance of going abroad for further study. 考虑再三，应该再给他一个出国深造的机会。

　　I have no interest in playing the guitar, talking of music. 谈到音乐，我对弹奏吉他不感兴趣。

　　四、有些分词已经转化为介词或连词，并且在意义上已有所变化。常用的有：given (考虑到，如果有，假定是,设想到), compared to /with /from(和...相比而言), considering ...(就……而论,照……看来), including (包括)，provided(that )(假如，如果), supposing (that )(假设，如果), seeing (that)(鉴于,既然，由于)等。此时，解题就不可再按常规来考虑，要根据他们的特殊用法进行理解和突破。例如：

Given his health condition, we had better not let him go there. 考虑到他的身体状况，我们最好不要让他去那里了。

　　Supposing that it rains tomorrow, what shall we do?  假如明天下雨的话，我们该怎么办？

　　Concerning this, I mentioned it in my speech just now. 关于这一点，我在刚才的演讲中提到过。

　　五、现在分词在句中作状语，句中存在可以暗示主语的因素，常通过句中人称代词的不同“格”的形式或物主代词形式暗示出该分词动作的逻辑主语。例如：

　　Going upstairs, a good idea struck her. 上楼时她突然想出了一个好办法。（由her 暗示出going 的逻辑主语就是she）

　　Looking through his composition , a new opinion came into his mind. 浏览着作文时，一个新观点在他的头脑中萌生了。（由his 暗示出looking through的逻辑主语就是he）

　　六、现在分词在句中作状语，其逻辑主语是表示泛指的one, we 或you。例如：

　　When smoking carelessly in the workshop, it is easy to cause a fire. 当(你)粗心地在车间里吸烟时，很容易造成火灾。（smoking的逻辑主语是表示泛指的one 或you）

　　While having dinner in a foreign family, a knife and fork is needed often.当在一个外国家庭用餐时，(你)往往需要一副刀叉。

　　七、现在分词作状语，其逻辑主语是其前面或后面的整个句子，该分词往往可以改写为一个由as 或which 引导的定语从句。例如：

　　The boy's parents died, leaving him an orphan. 这个男孩的双亲去世了，撇下他一个孤儿。（=The boy's parents died, which left him an orphan.）

　　His key was left in his office, making him not come into it. 他的钥匙落在办公室里了，使得他无法进去。（= His key was left in his office, which made him not come into it.）

　　巩固练习：请选出符合题意的最佳选项。

1. ______, tears came into her eyes.

A. Reading the letter     B. Having read the letter

C. While she was reading the letter

D. Her reading the letter

2. _____ this is not the right way to the town, what shall we do?

A. Supposed                    B. Supposing

C. Seeing                         D. Providing

3. _____ that she only has been learning the language for six months, her English is not too bad.

A. Considering                B. Realizing

C. Regarding                   D. The fact

4. _____ such heavy pollution already, it may now be too late to clean up the river.

A. Having suffered           B. Suffering

C. To suffer                     D. Suffered

5. ____ the general state of his health, it may take him a while to recover from the operation.

A. Given                          B. To give

C. Giving                        D. Having given

6. European football is played in 80 countries, ____ it the most popular sport in the world.

A. making   B. makes   C. made   D. to make

Keys:  1.C   2.B   3.A   4.A   5.A   6.A