一般时态/do/be
一般现在时
This song is often sung by children.（含被动语态）
一般过去时
This house was built in 1958.
一般将来时
Many buildings will be built in my home town.
过去将来时
He asked me how soon I would get ready.
进行时态/ing
现在进行时
The proposal is being considered now.
过去进行时
Mr Wu was in hospital .When we went to see him,he was being operated on.
将来进行时
I will be reading a book at 10:00 tomorrow.
过去将来进行时
He asked me what I should be doing six o'clock tomorrow.
完成时态/have done
现在完成时
Have the letters been posted ?
过去完成时
He came and told us that the work had been finished.
将来完成时
By the end of this year,the tall building will have been built.
过去将来完成时
I thought Sophia would have told you something.
完成进行时/have been doing（强调持续性）
现在完成进行时
We have been seeing quite a lot of each other recently.
过去完成进行时
He has been saying that for years.
将来完成进行时
He will have been studying Chinese seven years by 1980．
过去将来完成进行时
I knew by that time he would have been working there for 30 years.
我知道到那时他他就在那儿工作满30年了。
时态一致
当主句谓语使用现在时或将来时，从句的谓语根据具体情况使用任何时态
We hope that there will be many people at your party today.
当主句谓语使用过去时的时候，从句的谓语必须使用过去范围内的时态
He said he was writing a novel.
当从句是表示没有时间概念的真理时，从句的谓语应使用一般现在时
The teacher told them since light travels faster than sound, lightning appears to go before thunder.
当主句动词是表示命令、请求、要求、建议、劝告等的动词，从句谓语只能用虚拟语气，不能遵循时态一致原则
Our suggestion is that you（should）be the first to go．
