随着英语的逐渐演变，在某些简单句中，相对应的句子成分不能用单词进行描述。
主（多喝水）+ is great for your health.
I love 宾（踢足球）.
My hobby is 表（玩电脑游戏）.
I has bought a book(王先生写的)等等。
我们发现，在上面的模型里，没有办法用一个单词进行描述，所以在演变的过程中，出来一个新的语法成分，叫做非谓语动词短语（to do ,doing, done，注意done与did的区别）
注：
1、只加不定式作宾语的动词：plan, demand, promise, help, prepare, decide, refuse, choose, wish/hope, expect, fail, pretend, manage, determine, beg, arrange, threaten, claim, hesitate, happen等。
2、只加动名词作宾语的动词：admit, avoid, consider, escape, imagine, mind, miss, practice, suggest, advise, allow, permit, risk, prevent, resist, deny, forbid，advocate, forgive, acknowledge, postpone, delay, fancy, recall,finish/complete, acknowledge等
3、下面这些短语只能加doing作宾语：be addicted to, be accustomed to, get down to, lead to ,contribute to, devote oneself to , object to, look forward to, owing to, become/get/be used to, pay attention to等等。
4、既可以加to do, 也可以加doing的动词，且意思很相近的动词：intend, attempt, continue, begin, start等。
5、接to do 和doing 作宾语意义差别很大的动词：mean, forget, try, go on等。
To swim in the river is a great pleasure.（不定式）
Smoking does harm to the health.（动名词）
He pretended not to see me.（不定式短语）
I enjoy listening to popular music.（动名词短语）
Our monitor is always the first to enter the classroom.（不定式短语）
The boy playing football(动名词短语) is my brother
The dog killed by a car(过去分词短语) is very fierce.
注意：非谓语动词短语作定语时，要放在修饰词的后面，形容词做定语时，放在修饰词的前面。
