现在进行时:I am doing my homework.
My mother is cleaning the house.
一般现在时:I often go to school by bike.
She always goes for a walk after supper.
一般将来时:He will go to Beijing tomorrow.
We will finish the job in three days.
一般过去时:She went to Shanghai yesterday.
I did my homework last night.
现在完成时:I have been a teacher for 12 years.
I have finished my homework.