yesterday,last week ,in  the  past ,in 1993,at that time,once,during the war,before,a few days ago,when 等等.
（句子中谓语动词是用一般过去时还是用现在完成时，取决于动作是否对现在有影响）。
Have you had your lunch? 你吃过午饭了吗？（你现在不饿吗？）
Yes,I have. 是的，我已经吃过了。（已经吃饱了，不想再吃了。）
When did you have it? 你是什么时候吃的？（关心的是吃的动作发生在何时。）
I had it about ten minutes ago. 我大约是十分钟以前吃的。）
Used to do something 表示过去常做而现在已经停止了的习惯动作。
I used to work fourteen hours a day. 我过去常常一天干十四个小时。
I ate it at 6：45。我在六点四十五分吃了。

（3）带有确定的过去时间状语时，要用过去时。如：
yesterday（昨天）、two days ago…（两天前…… ）、last year…（去年…）、the other day（前几天）、
once upon a time（很久以前）、 just now（刚才）、in the old days（过去的日子里）、before liberation（解放前…）、
When I was 8 years old（当我八岁时…）、at+一个时间点
Did you have a party the other day？前几天，你们开了晚会了吗？
Lei Feng was a good soldier.雷锋是个好战士。
注：在谈到已死去的人的情况时，多用过去时。

（4）表示过去连续发生的动作时，要用过去时。这种情况下，往往没有表示过去的时间状语，而通过上下文来表示。
The boy opened his eyes for a moment，looked at the captain，and then died.
那男孩把眼睛张开了一会儿，看看船长，然后就去世了。

（5）表示过去一段时间内经常或反复的动作。常与always，never等连用。
Mrs. Peter always carried an umbrella.彼得太太过去老是带着一把伞。
（只是说明她过去的动作，不表明她现在是否常带着伞。）
比较：
Mrs. Peter always carries an umbrella.彼得太太老是带着伞。
（说明这是她的习惯，表明她现在仍然还习惯总带着一把伞）
Mrs. Peter is always carrying an umbrella.彼得太太 总是带着一把伞。
（表示说话者对这一动作或行为厌烦）
I never drank wine.我以前从不喝酒。
（不涉及到现在，不说明现在是否喝酒）

（6）如果强调已经终止的习惯时要用 used to do（过去常常做，而现在不那样做了）
He used to drink alcohol.他过去喝酒。
（意味着他现在不喝酒了。喝酒这个动作终止了）
I used to take a walk in the morning.我过去是在早晨散步。
（意味着现在不在早晨散步了）
比较：
I took a walk in the morning.我曾经在早晨散过步。
（只是说明过去这一动作）

（7）有些句子，虽然没有表示过去确定时间的状语，但实际上是指过去发生的动作或存在的状态的话，也要用过去时。
I didn''t know you were in Paris.我不知道你在巴黎。
（因为在说话时，我已经知道你在巴黎了。这句话指的是说话之前，所以只能用过去时表示。实际上，这句话暗指：But now I know you are here.）
I thought you were ill.我以为你病了呢。
（这句话应是在说话之前，我以为你病了。但是现在我知道你没病）

一般过去时三变技巧:
一变：肯定句变为否定句
技巧1.当句中含有情态动词或助动词could，would，should等时，可直接在其后面加not构成否定句。例如：
I could get you a concert ticket. → I could not / couldn't get you a concert ticket.
技巧2.当句中含有系动词was，were 时，可直接在其后加not构成否定句。例如：
I was on the Internet when you called me. → I was not / wasn't on the Internet when you called me.
技巧3.当句中谓语是除情态动词、助动词、系动词was, were以外的动词时，在该动词之前加did not / didn't，动词还原，构成否定句。例如：
The famous singer sang some Chinese songs. → The famous singer did not / didn't sing any Chinese songs.

二变：陈述句变为一般疑问句
技巧1.移动词语的位置。将was，were, could，would，should等移到句首。例如：
He could pack his things himself. → Could he pack his things himself?
技巧2.添加助动词did。谓语是除情态动词、助动词、系动词was, were以外的动词时，在主语之前加did，动词还原。例如：
Mr Li looked very old. → Did Mr Li look very old?

三变：陈述句变为特殊疑问句
技巧1.确定疑问词：人who / whom，物what，地点where，时间when / what time，原因why，频率how often，长度how long，距离how far等等。例如：
They gave the concert last night. → When did they give the concert?
技巧2.辨认结构形式：疑问词+情态动词/助动词/ was / were / did +主语+...? 例如：
The accident happened near the station. → Where did the accident happen?

考点名称：疑问副词

• 疑问副词：
  用来引导特殊疑问句，表示时间，地点，方式，原因等。
  常见的有：when,where,how,why等。

• 疑问副词的用法：
  1.疑问副词是问何时、何地、如何、因何的副词，主要有when, where, how, why。
  
  2.疑问副词用在句首。
  How long have you been staying in America?
  你在美国待多久了?

  3.疑问副词在句中引导名词子句。
  I want to know where she has gone.
  我想知道她去哪里了。

  4.疑问副词后接不定词构成的名词片语，在句中可以作主词、受词或主词补语。
  How to solve the problem gives him a bad headache.
  如何解决这个问题使他伤透脑筋。
  （How to solve the problem作主词。）
  I don't know how to answer the question.
  我不知道如何回答这个问题。
  （how to answer the question作受词。）
  The patient is in urgent need the medicine, but the problem is where to get it.
  这个病人急需这种药,但问题是哪里能找到。
  （where to get it作主词补语。）

  5.疑问副词引导的名词子句可作主词、受词或主词补语。
  When we are to start the competition hasn't fixed yet.
  我们什么时候开始比赛还没有定下来。
  （When we are to start the competition作主词。）
  She asked her husband where he had been.
  她问她丈夫去哪里了。
  （where he had been 作受词。）
  The question is when we can finish our work.
  问题是我们何时能完成我们的工作。
  （when we can finish our work作主词补语。）

• 疑问代词与疑问副词的区别：
  1. 疑问代词做对陈述句的主语，宾语或定语提问，即做句子的主语，宾语或定语，如what, who/ whom, whose.
  eg. Who is talking ? What can you see?
  Whose shirt is this?
  2.疑问副词对时间，地点，方式等状语提问，如when, where, how 等.
  eg. When is your birthday? Where are you going?
  How do you know?
  常见的疑问代词：what  who  which  whom(只做宾语）
  疑问副词：how  where  when
  还有whether是疑问连接词。

考点名称：状语从句

• 状语从句：
  指句子用作状语时，起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。
  根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。
  状语从句一般由连词(从属连词)引导，也可以由词组引起。
  从句位于句首或句中时通常用逗号与主句隔开，位于句尾时可以不用逗号隔开。

• 状语从句分类:
  1、时间状语从句
  常用引导词：
  when, as, while, as soon as, while, before, after, since , till, until
  特殊引导词：
  the minute, the moment, the second, every time, the day,the instant, immediately , directly, no sooner … than, hardly …when, scarcely … when
  I didn't realize how special my mother was until I became an adult.
  While John was watching TV, his wife was cooking.
  The children ran away from the orchard(果园) the moment they saw the guard.
  No sooner had I arrived home than it began to rain.
  Every time I listen to your advice, I get into trouble.
  
  2、地点状语从句
  常用引导词：
  where
  特殊引导词：
  wherever, anywhere, everywhere
  Generally, air will be heavily polluted where there are factories.
  Wherever you go, you should work hard.
  
  3、原因状语从句
  常用引导词：
  because, since, as, for
  特殊引导词：
  seeing that, now that, in that, considering that, given that, considering that, as much as, so much as
  My friends dislike me because I'm handsome and successful.
  Now that everybody has come, let's begin our conference.
  The higher income tax is harmful in that it may discourage people from trying to earn more.