现在分词的概念：

现在分词（PresentParticiple）(又称-ing形式)，是分词的一种，是非限定动词，即在句子里面不能单独充当谓语，但能充当其它的一些成分（定语，表语，补语和状语）。一般式：doing；一般被动式：being done；完成式：having done；完成被动式：having been done。所有否定式都是在－ing前面加not。

1、现在分词的两个基本特点
1）在时间上表示动作正在进行。例如：a developing country.一个发展中的国家，boiling water沸水，
      rising sun冉冉升起的太阳。（试比较：a developed country一个发达国家，boiled water沸水，risen sun
     升起的太阳）　　
2）在语态上表示主动。例如：the ruling class统治阶级，the exploiting class剥削阶级。（试比较：
      the ruled class被统治阶级，the exploited class被剥削阶级）
2、现在分词的基本功能
1）现在分词作定语，表示正在进行的或主动的动作。也可以说明被修饰词的性质和特征，此时可换
     成相应的定语从句。
例如：　　
①There was a terrible noisefollowing the sudden burst of light.　　
②Hesaw a flying bird and raised his bow.　　
③I was satisfied with the exciting speech.　　
2）现在分词作状语时，可作时间、条件、结果、原因和伴随状语，表示正在进行的或主动的动作。
      此时分词的逻辑主语就是主句的主语，因此要注意人称、时态和语态的一致性。
例如：　　
①The visiting minister expressed his satisfaction with the talks, adding that he had enjoyed his stay here.　　
②European foot ball is played inmore than 80countries, making it the most popular sport in the world.　　
③Seeing from the top of the hill,we can find that the city looks more beautiful.　　
3）现在分词作补足语，表示正在进行的或主动的动作。
例如：　　
①Soon they could see the steam rising from the wet clothes.　　
②The missing boys were last seen playing near the river.　　
4）现在分词的独立主格结构作状语。
例如：　　
①Withhislipsstilltrembling,hecouldn'tsayaword.　　
②“Mama!”hecriedsuddenly,tearsrollingdownhischeeks.
“妈妈！”他突然哭着喊，泪水从他的脸上流下来。
（这里需要用现在分词的独立主格结构tearsrollingdownhischeeks作状语。）　　
③Weather permitting,we'llgo to the Great wall.如果天气允许的话，我们就去长城。
（这里需要用现在分词的独立主格结构Weatherpermitting作状语。）　　
3、现在分词的否定结构　现在分词的否定式由“not+现在分词”构成。
如：　　
Not knowing where togo, she went to the police for help.　　
她不知道该往哪儿走，就去请警察帮助。(现在分词一般式的否定结构)　　
Nots eeing John, I asked where he was.　　
我看不见约翰，于是问他在何处。（现在分词一般式的否定结构）　　
Not being seen by any one, the thiefe scaped.　　
那个贼趁无人看见时逃跑了。（现在分词被动式的否定结构）　　
Not having done it right, I tried again.　　
我由于没有做对，所以又试了试。（现在分词完成式的否定结构）

现在分词的用法：

1）做表语：
如：He was very amusing.
        That book was rather boring.
很多动词的现在分词都可以作表语：exciting, interesting, encouraging, disappointing, confusing, touching, puzzling.
2）作定语：
上面所出现的现在分词都可以用作定语,修饰一个名词：
如：That must have been a terrifying experience.
        I found him a charming person.
现在分词短语还可以放在名词的后面修饰名词,相当于一个定语从句：
如：There are a few boys swimming in the river.
        There is a car waiting outside.
3）作状语：
现在分词短语可以表示一个同时发生的次要的或伴随的动作：
如：Following Tom, we started to climb the mountain. 
        Opening the drawer, he took out a box.
        Taking a key out of his pocket, he opened the door.
现在分词短语还可以表示原因，相当于一个原因状语从句：
如：Not knowing her address, we couldn't get in touch with her.
        Being unemployed, he hasn't got much money.
现在分词短语还可以表示时间，相当于一个时间状语从句：
如：Hearing the news, they all jumped with joy.
        Returning home, he began to do his homework. 
        Jim hurt his arm while playing tennis.
        Be careful when crossing the road.
        Having found a hotel, we looked for some where to have dinner.
        Having finished her work, she went home.
4）作宾补：
现在分词在一些动词之后可以做宾语的补语：
例如：see, hear, catch, find, keep, have等。
如：I see him passing my house every day.
        I caught him stealing things in that shop.
        I smelt something burning.
        She kept him working all day.

现在分词其他用法解析：

1、现在分词一般式的用法：
现在分词的一般式所表示的动作与主语动作同时发生：
如：When we arrived, we found him sleeping. 我们到达时发现他在睡觉。
         Living in the 示的动作也可略早于或迟于谓语动作，但两者之间没有时间间隔：
如：Seeing nobody at home, he decided to leave a note. 发现没有在家，他决定留个字条。 
         He went home, finding the door locked. 他回到家，发现门是锁着的。当现在分词所表示的动作略迟于谓语动作时，现在分词通常位于句末。

2、现在分词完成式的用法：
现在分词的完成式主要表示发生在谓语动作之前的动作：
如：Having been there once, she knew the place quite well. 由于去过那儿一次，她对那地方很熟悉。
        Having failed twice, he didn't want to try again. 他已经失败了两次，不想再试了。
注：（1）现在分词的一般式和完成式均可表示已完成或先于谓语的动作，但有区别：现在分词所表示的动作虽然可以先于谓语动作，但两者之间没有时间间隔，而现在分词的完成式所表示先于谓语的动作则与谓语动作有一定的时间间隔：
如：Locking the door, he went out. 锁好门之后，他就出去了。
        Having invited him here to speak, we'd better go to his lecture. 既然我们请了他来作报告，我们最好去听一下。
有时即使是分词动作与谓语动作几乎同时发生，但如果要强调分词动作的完成性，也应用现在分词的完成式：
如：Having bought our tickets, we went into the theatre. 我们买好票后就走进剧场。
（2）现在分词的完成式一般不用作定语：
误：Do you know anyone having lost a cat? 你知道有谁丢了一只猫吗？
误：I want to talk to the person having broken the window. 我想同打破窗户的人谈谈。
若将以上现分词的完成式改为一般式也不可以（因为现在分词作后置定语时通常只表示与谓语动作同时或几乎同时发生的动作，而不能先于谓语动作而发生）：
误：I want to talk to the person breaking the window.

3、现在分词被动式的用法：
当要表示一个被动动作时，现在分词就用被动形式。现在分词的一般式和完成式均有被动式形式：
（1）现在分词一般式的被动式：主要表示现在正在进行的动作，也可表示与谓语动作同时发生的动作：
如：Who is the woman being operated on? 正在动手术的女人是谁?
         I saw him being taken away by the police. 我看见他被警察带走。
注：有时现在分词一般式的被动式所表示的动作也可发生在谓语动作之前（此时的现在分词通常用于表示原因，且多为状态动词）：
如：Not having a car, he finds it difficult to get around. 由于没车，她感到行动很困难。
（2）现在分词完成式的被动式：主要表示发生在谓语动词之前且已经完成的动作。
如：The subject having been opened, he had to go on with it. 话题已经开始了，他不得不谈下去。
        Having been written inhaste, the book has many mistakes. 这书因写得仓促，所以错误不少。
比较：Being so ill, she can't go to school. 由于病得那么严重，她不能去上学。
            Having been ill for a long time, he needed time to recover. 由于病了很长时间，他需要一段恢复的时间。