现在进行时
进行时：说话的同时，一个动作正在进行之中。
非谓语：doing，to do
一句一谓
他正在看电视。
He is watching TV.
这个女孩很漂亮。
This girl is very beautiful.
Tom正在打篮球。
Tom is playing basketball.
Marry正在跳舞。
Marry is dancing.
Jack正座在椅子上。
Jack is sitting on the chair.

They are coming to my home.
他们将要来我家。
Come=短暂（非延续性）动词
短暂动词ing=将来
They are going to ride a bike.
他们打算骑自行车。
Be going to do sth.表示将来与will互换即可。
过去进行时
昨晚7点，Jeerry正在做功课。
At7:00 last night,Jery was doing homework.
They were leaving their country.
他们曾经打算离开他们的国家。

我正在看书。
I am reading a book.
他们正在操场上跑步。
They are running on the playground.
她正在教室里画画。
She is drawing a picture in the classroom.
They are arriving in the airport.
它们正在到达机场上。
昨天下午3点，jerry和marry正在打乒乓球。
At 3:00 p.m. yesterday , jerry and marry were playing the ping pong.
那个时候，她正在卧室里睡觉。
At that time, she was sleeping in the bedroom.