一般现在时:The moon moves around the earth.
As soon as i arrive here,i will telephone you.
一般过去时:I saw him in the street yesterday.
When we were girls,we used to dance and sing together.
现在进行时:He is writing a letter to his parents now.
He is always helping others.
过去进行时:While i was watching TV,my husband was reading the newspaper.
My grandfather was always helping others before he died.
一般将来时:Shall we go to the park?
It's going to rain.
过去将来时:Last Sunday we were going to go for a picnic but it rained.
Little did they know they were to reunite ten years later.
现在完成时:We have seen the film before.
It's the most exciting moment i've experienced.
过去完成时:By the time we got there,the play had already begun.
If i had known it i would have told you.
现在完成进行时:I have been waiting for you for one hour.
What have you been doing since i saw you last time?