英语语法：动名词和现在分词的区别

英语中的动名词和现在分词在形式上都是由“动词原形+ing”形式构成的，大家在学习中经常容易混淆！
第一、动名词和现在分词均可以作“定语”，用以修饰名词：动名词表示名词的“用途、功能”等；而现在分词修饰名词的“动作、行为”，可以转换为定语从句。
典型例句：
(1) There is a swimming pool in the park.
(2) Be quiet, please. There is a sleeping baby on the sofa.
例句1中的swimming表明池子的用途；例句2中的sleeping表明baby的动作状态，可以转换为一个定语从句：
There is a baby who is sleeping on the sofa.
第二、动名词和现在分词均可以作“表语”：动名词作表语时，相当于一个名词，主语和表语可以互换位置；现在分词作表语，相当于一个形容词，主语和表语不可互换位置。
典型例句：
(1) His hobby is swimming. = Swimming is his hobby.
(2) The news is exciting.
备注：在一些资料中，把类似于exciting这样以"-ing"结尾的词叫作-ing形容词，其主语为物，-ing形容词表示主语的特征和特点等。
第三、可以根据特殊疑问句的疑问词来判断：疑问词为what，则为动名词；疑问词为how，则为现在分词。
典型例句：
(1) -How was the movie last night ?
-Amazing.
(2) -What is your brother's hobby ?
-Reading and writing.
【区分现在分词和动名词的一些窍门】
(1) 可以构成复合形容词的v-ing，一定是现在分词。
He was smart and hard-working before.
(2) 否定祈使句中的v-ing，一定是动名词。
No smoking in the library.
(3) 介词或者介词短语后的v-ing，一定是动名词。
I will stay at home instead of going shopping tonight.
(4) 有物主代词、指示代词、所有格、冠词以及some/much等词修饰的v-ing，一定是动名词。
He showed us his writing.