现在时
一般现在时，表示客观事实或真理。结构：主语＋动词原形（第三人称单数时动词加s）如：
He lives in Nanjing.
You look very hungry now.
2.现在进行时，表示现在正在进行或继续的动作，状态。如：
He is writing a letter at present.
It is raining now.
John is doing his assignment right now.
3．现在完成时, 表示过去的动作对现在有影响或过去的动作持续到现在。如：
He has just come back.
I have already seen it.
I have lived here for ten years.
4.现在完成进行时,表示从过去某时开始，一直继续到目前的动作。其特点在强调“动作的继续”性质。如：
He”s very tired, he has been working hard all day.
过去时
一般过去时,表示过去的事情，动作，状态或过去的习惯。如：
Bill was very thin when he was a child.
John went to Shanghai yesterday.
过去进行时,表示过去某时正在进行的动作。如：
I was watching TV at eight o”clock last night.
He was sleeping when I arrived.
过去完成时,表示过去某个动作发生以前的动作。如：
The train had gone before we reached the station.
After you had gone, I went to sleep.
过去完成进行时,表示过去某个动作发生以前的持续的动作。如：
We had been waiting for him an hour when he arrived.
将来时
一般将来时, 表示将来的动作或状态。如：
I will go to the movies tonight.
It will be fine tomorrow.
将来进行时，表示将来某时正在进行的动作。如：
When we get there, they will be eating.
将来完成时，表示将来某点时间或将来某动作之前业已完成的动作。如：
By next May he will have lived here for six years.
I shall have finished the book when you come next time.
将来完成进行时, 表示将来某点时间或将来某动作之前业已完成的动作的继续。如：
By June, we shall have been learning English for three years
看两个视频
http://foxrouge.blogchina.com/1473259.html http://foxrouge.blogchina.com/1473245.html参考资料：http://zhidao.baidu.com/question/84785957.html?si=1