to do不定式 用在句首时候 一般作目的状语
如：To make herself (well) understood by the students,Miss Lee drew a picture on the blackboard.
doing 动名词 放在句首一般做主语
如：Working is good exercise.
当然有时候也用it做形式主语 来代替动名词（真正主语）
下面是动名词详
动名词的形式,以动词write为例：
主动语态 被动语态
一般式 writing being written
完成式 having written having been written
否定式：not +动名词
动名词作主语：
Working is good exercise.
It is fun having guests for the weekend.
当动名词复杂而长时,为保持句子的平衡,可后置,it 为句子的形式主语
It is no use trying to persuade him.
It is no good talking to a person like her.
动名词作宾语：
A、及物动词的宾语
（suggest,finish,stop,mind,enjoy,put off,practise,advise,consider…)
The doctor advised taking exercise.
do +限定词（the,my,some,much,…)+doing
Who will do the cooking?
B、作介词的宾语
He has some difficulty in keeping five children in school.
C、作形容词worth,busy的宾语
He was worth teaching.
The teacher is busy correcting the students’ exam papers.
D、need,require,want作为“需要”,动名词的主动表示被动或用不定式的被动.
The window needs cleaning(to be cleaned).
动名词的复合结构
物主代词或名词所有格+动名词构成复合结构.物主代词或所有格是动名词的逻辑主语.
I remember Wei Fang’s going there.= I remember going there.
如果不是句子的开头,可以用名词的普通格或人称代词的宾格
Would you mind my(me) opening the window?
如果动名词的逻辑主语是无生命的东西,多用普通格.
Is there any hope of our team winning the game?
