几种容易混淆的时态比较(一）之一
一、一般过去时与现在完成时的用法比较。
1.一般过去时所关心的是过去之事,与现在无联系，常带有表示过去某个时间的状语；现在完成时所关心的是过去发生的事，与现在有影响和联系，对现在产生某种结果；现在完成时强调过去与现在的联系，语句译成汉语后常常带有已经了或了的含义。
Ａ.I ________(lose) my pen.Can you lend me yours?
Ｂ.Why don't you buy one?
Ａ.It _______(fall) into the river only a moment ago when I washed my hands. Now I've got to fill in a form with a pen.
2.现在完成时与for或since引起的短语连用时，表达从过去开始的动作或状态延续至今，而一般过去时与for＋一段时间连用时，只指过去的动作或状态在过去延续了多长时间。
We___________(stay) here for three weeks. I think we are going to stay another two weeks.
（说话时人还在）
He __________(stay) here for three weeks last year.
（并不表示现在是否在）
3.一般过去时带有表示过去某时刻的时间状态，如yesterday,last year(month,week,night)，in 1980
eg. When _____you_______ (come)?
I ______(come) the day before yesterday.
4.现在完成时所带时间状语包含说话时在内,如today,this week(month,year),these days(years)或与说话时非常接近，如recently,just,in(during) the past three years。
eg.I___________(learn) over three hundred words this year.
Great changes _______( take) place in the last ten years.
1.Oh,what______(happen)?Why is there so much blood on the playground?
Your father ________(kill) a cock just now.
2.I'm so glad that you _______(make) such good progrcess this term.
3.I saw an Englishman on my way home.
________ you ________(talk) to him?
No.He was speaking to a policeman.
4.Last year I went to study medicine in a university in Japan.
How long ______ you _____(study) there?
5.Being very angry,he ____(beat) the table and ____(say) some rude words.
二、一般过去式与过去完成时的区别。
1.一般现在时表示过去某一时间内发生的动作或存在的状态，而过去完成时则表示过去某一动作或时间之前发生的动作或存在的状态。 一般过去时与现在相比，强调过去，而过去完成时则与过去相比，强调过去的过去。
我们来比较下列句子：
The meeting _________(start) at six o'clock.
start的动作发生在at six o'clock。
The meeting ___________( start) when we arrived at the hall.
start的动作发生在过去的动作arrived之前。
2.过去完成时可表示过去某个时间之前开始的动作或状态的延续，与since或for引导的时间状语连用。
He ___________( work) in the month for