句型：

It is time for sb. to do sth　 "到……时间了"　 "该……了"

It is time sb. did sth. "时间已迟了"　 "早该……了"

It is time for you to go to bed.　 你该睡觉了。

It is time you went to bed.　　　你早该睡觉了。

would (had) rather sb. did sth.　表示'宁愿某人做某事'

I'd rather you came tomorrow.

wish, wonder, think, hope 等用过去时，作试探性的询问、请求、建议等。

I thought you might have some. 我以为你想要一些。

比较：

一般过去时表示的动作或状态都已成为过去，现已不复存在。

Christine was an invalid all her life.

(含义：她已不在人间。)

Christine has been an invalid all her life.

(含义：她现在还活着)

Mrs. Darby lived in Kentucky for seven years.

(含义：达比太太已不再住在肯塔基州。)

Mrs. Darby has lived in Kentucky for seven years.

( 含义：现在还住在肯塔基州，有可能指刚离去)

注意： 用过去时表示现在，表示委婉语气。

动词want, hope, wonder, think, intend 等。

Did you want anything else?

I wondered if you could help me.

2)情态动词 could, would.

Could you lend me your bike?

used to / be used to

used to + do："过去常常"表示过去习惯性的动作或状态，但如今已不存在。

Mother used not to be so forgetful.

Scarf used to take a walk.　 (过去常常散步)

be used to + doing： 对……已感到习惯，或"习惯于"，to是介词，后需加名词或动名词。

He is used to a vegetarian diet.