1.When one verb follows another verb, the structure is usually verb +ing or verb +to

当一个句子里有两个动词的时候， 其中一个动词会用ing 或者to的形式。

often we use -ing for an action that happens before the first verb or at the same time.

often we use to .. for an action that follows the first verb

e.g.   They denied stealing the money .   ( Steal happened before deny )

e.g.    I enjoy going out  (  enjoy and go out happens at the same time )

e.g. I want to go out ( go out happens after want )

2. V+ing for two or more actions at the same time or follows quickly.

当两个动作同时发生的时候，任意一个动词用ing形式。

When 2 actions occur at the same time , and are done by the same person or thing , we can use v+ing for one of action .

  e.g.  whistling to himself , he walked down the road.

当两个动作紧接着发生的时候， 前一个动作用Ing形式。

when one action follows very quickly after another done by the same person or thing . we can use v+ing for the first action .

e.g. Putting on his coat , he left her hands in the air .

3.V+ing to explain a reason

Ing形式放在句首用来表示原因

It can be used instead of a phrasing starting with  as, since , because .

e.g. being poor , he didn't spend much on clothes.

e.g. Feeling hungry , he went into the kitchen and opened the fridge.

4. V+ ing to reduce relative  clause

从句里的进行时态

How to reduce :  v+ing and remove the pronoun.

We use v+ing  reduce relative  clause  to say what somebody or something is /was doing at a particular time .

e.g. Do you know the woman talking to Tom ?  (original structure-  Do you know the women who is talking to tom )

when we are talking about things ( and sometimes people ), we can use -ing to say what something does all the time , not just a particular time.

e.g. The road joining the two villages is very narrow .  （original structure - the road that joins the two villages is very narrow )

5 If a preposition (in /for /about /at/after etc.   ) is followed by a verb, the verb ends in -ing .

e.g. interested in doing / good at doing / fed up with studying / only for cutting

6.some verbs are often followed by -ing

Stop / Delay / Fancy / Mind / Enjoy / Consider / Admit /Miss /Suggest /spend/defer/forgive/escape

Invlove /Finish / Postpone / Imagine/ Avoid / Deny /Risk/ Enjoy/ Mind /dislike/resent/dread/save/resist

Give up / Put off / Carry on , go on /  Keep or keep on /used to /have difficulty /detest

e.g.   I enjoy reading.         Would you mind closing the window.  

The negative form is  " not   -ing "

e.g.  Do you suggest not going out ?  

6.  With some verbs we can use  the structure verb+somebody + ing

Imagine / stop / keep  

e.g. sorry for keep you waiting so long.

The passive form is ( being done )  

I don't mind being kept waiting.

7.V+ing as subject

e.g.  Brushing your teeth is important

e.g. Smoking causes lung cancer.