什么情况下要加ing
作谓语的情况：这时候的动词加ing前面必须加上be动词，形成be+动词ing（现在分词）作句子谓语，构成进行时态句子。
动词加ing做非谓语的情况
1.动词作介词的宾语要加ing(动名词)
2.部分动词用动词做宾语。做宾语的动词要加ing(动名词)！
3.一些固定句式后面要加动词ing(现在分词)。
4.动词修饰名词做后置定语时，要加ing(现在分成)！
5.动词做主语和表语时，动词要加ing(动名词)。
例如
He is reading a book now.他正在看书。
He was watching TV when his mother came in.他妈妈进来时，他正在看电视。
They've been waiting for you for three hours.他们等你三个小时了。
I'm looking forward to seeing you again.我期盼着再次见到你。
The boy is so excited about hearing from his mother.男孩为收到他妈妈的来信很兴奋。
I Practising speaking English Every day.我每天练习说英语。
I have finished reading three books.我已经看完三本书。
The old man Enjoys living in the country.这老人喜欢住在农村。
We have fun Playing in the park on Sunday.星期天我们在公园玩得很开心。
Most students have problems speaking English.大多数学生讲英语有困难。
There is a boy Crying over there.那边有个男孩在哭。
I felt something moving in the house.我感到房子里有东西在动。
I heard someone singing in the next room.我听见有人在隔壁唱歌。
Swimming is very popular in summer.夏天游泳很受欢迎。
His job is teaching English.他的工作是教英语。
