请问现在分词做后置定语和分词做状语的区别 ，分词做状语依据什么写现在分词还是过去分词

定语是用来描述名词（一件东西或是一个人或是一件事情）的,如a red rose中red就是定语,描述的是rose的颜色.分词也可以用来描述名词,并且分词的这个动作就是这个名词发出来的或是由这个名词来承受这个动作,如a flying bird,fly这个动作就是bird发出的；a broken cup中的broken是个过去分词,cup被打破了,承受了break这个动作.状语往往是用来描述某一个动作的,但是分词状语有很大的不同,它一般是用来描述句子主语的特征或者状态.如 Looking at me,she didn't say anything.looking这个动作是句子的主语she发出来的,和say是同步发生的一个伴随动作.又如,Not knowing my name,she asked me for it.这里的not knowing说的是原因,正是因为他不知道我的名字,所以才问我.我相信这么讲了过后你仍然还是模棱两可.分词是高中阶段最重要的语法项目,也是最复杂的语法项目,建议多背课文,多理解,多分析。

在用状语的时候，根据判断句子的需要，例如被动-vpp，主动-ving，将来-to do句子中主语谓语所存在的关系，

1.分词或分词短语作状语时,可以表示时间、原因、让步、条件,方式或伴随状况.通常可转换成相应的状语从句；表示方式或伴随状况时可以转换成并列句或非限制性定语从句.例如：

Put into use in April 2000 (=When it was put into use in April 2000),the hotline was meant for residents reporting water and heating supply breakdowns.(2005上海) 分词短语作时间状语

Blamed for the breakdown of the school computer network (=Because she was blamed for the breakdown of the school computer network),Alice was in low spirits.(2006福建) 分词短语作原因状语

Given time (=If he is given time),he’ll make a fist-class tennis player.（03北京）分词短语作条件状语

We often provide our children with toys,footballs or basketballs,thinking that all children like these things.(= and think that all children like these things.) (2006全国3) 分词短语作伴随状语

2.有时为了强调,分词前可带when,while,if,though,as if,unless等连词一起作状语,以便使句子的意思更清楚、更连贯.例如：

When comparing different cultures,we often pay attention only to the differences without noticing the many similarities.（2006浙江）

Though tired,he still continued reading.3.现在分词和过去分词作状语时的用法比较.

不管是现在分词还是过去分词单独作状语,其逻辑主语必须与主句的主语一致.分词作状语通常可转换成一个相应的状语从句或并列句,如果状语分句或并列句中的谓语动词为被动结构,就用过去分词；如果状语分句或并列句中的谓语动词为主动结构,就用现在分词.例如：

When compared with the size of the whole earth ,the biggest ocean does not seem big at all.（04湖北）

分词部分相当于When the biggest ocean is compared with the size of the whole earth,主语与分词是被动关系,所以用过去分词.

When comparing it with the size of the whole earth,we find that the biggest ocean does not seem big at all.

When we compare it with the size of the whole earth...主语与分词是主动关系,所以用现在分词.

Faced with a bill for＄10,000(=Because he is faced with a bill for＄10,000),John has taken an extra job.(2006全国2)

Whenever he was asked why he was late for class,he would answer carelessly,always saying the same thing (= and he would say the same thing).（2006江苏）