什么地方大量回收锯末:请教~~关于was/were和did

was和were是be动词，和am is are 是一类的，什么地方用am is are,什么地方就可以用was和were表示过去
did 是do 的过去式，既可以是实意动词也可以是助动词，和do的用法一样

般过去时表示过去某个时间发生的动作或存在的状态。常和表示过去的时间状语连用。如:last year, yesterday.
一般过去时由动词的过去式表示,动词be有was, were两个过去式,was用于第一、三人称单数,were用于其他情况。在构成否定及疑问句时,一般都借助助动词did, 动词be有其独特的疑问及否定形式(基本上和一般现在时一致)。
一般过去时的用法

1）在确定的过去时间里所发生的动作或存在的状态。
时间状语有：yesterday, last week, an hour ago, the other day, in 1982等。
Where did you go just now?

2）表示在过去一段时间内，经常性或习惯性的动作。
When I was a child, I often played football in the street.
Whenever the Browns went during their visit, they were given a warm welcome.

3）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.

4) 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。
1）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?

不可能两个同时使用！当第三人称或第一人称时，用“was"，第2人称或第复数时，用”WERE‘。当句子有动词时，dance, run do ,等，用“DID’