现在完成时及一般过去时区别.doc

现在完成时和一般过去时的区别

1. 定义不同：现在完成时表示现在已经完成的动作，或者过去发生的动作或存在的状态一直持续到现在；而过去时表示过去存在的状态或发生的动作。如
² She was very naughty when she was 10 years old. 她十岁的时候十分淘气。这里用过去时说明她过去（十岁时）存在的状态（淘气的状态）。
² He went to the park yesterday. 他昨天去公园了。这里用过去时说明过去（昨天）发生的动作（去公园）。
² She has finished her homework. 她已经完成她的作业。这里要用完成时说明完成作业这个动作已经发生和结束。
² She has been here for ten years.她已经住在这里十年了。这里要用完成时说明她住在这里这个动作或状态一直延续到现在（10年了），而且还可能一直延续下去。
2. 强调重点不同，现在完成时强调现在，强调现在已经完成的动作或持续到现在的状态和动作；而过去时强调的是过去发生的动作或存在的状态（现在那个状态已经不存在了）。
² The old man died yesterday. 那老人昨天死了。强调死亡发生在昨天。
² The old man has died. 那老人已经死了。强调死亡成为事实，die这个动作已经完成。
² The old man has been dead for about 20 hours. 那老人死了大约20个小时了。强调be dead 这个状态持续了约20个小时了。
3. 所接的时间状语不一样，现在完成时跟模糊的时间状语连用或不用时间状语；过去时通常跟具体过去时间状语连用。
l 常跟现在完成时用的时间状语有：so far, till, until, In the past ten years, up to now, since… ago, for…, now, already, yet, ever, never, before, recently, lately等 。
l 常跟过去时的时间状语：yesterday, last week, last year, last month, the day before yesterday, just now, in 1980等过去的时间。
l 常见的同时可以用在过去时和完成时的时间状语：this morning, tonight, before, recently, lately.
例子：
² I have had 10 dictionaries up to now.
² She has finished her test in past years.
² I haven’t seen you before.
² They have been there for a long time.
² Now he has grown up.
² I finished my homework this morning.
² I have finished my homework this morning.
² She was 1.5 meters last year. Now she has been much taller.
l 注意：现在完成时通常不跟过去时间连用。如果句子中出现yesterday, last week等过去时间，要用过去时。(部分通用的时间状语除外)
² She has died yesterday. (错)
² She died yesterday.(对)
² I have seen him last week.（错）
² I saw him last week. (对)
² I have seen him there before. (对)
² I saw him there before. (对)
4. 现在完成时使用时易错的地方：
l 过去分词规则变化和不规则变化弄错，不规则动词要特别记忆；
l 现在完成时不跟过去时间状语连用，除通用时间状语外。
l 现在完成时中终止性动词（非延续性动词）不跟一段时间连用，使用时要转化成延续性动词。常见的终止性动词和延续性动词的转化：

终止性动词
延续性动词
终止性动词
延续性动词
Buy
Have
Catch a cold
Have a cold
Borrow
Keep
Put on
Wear
Open
Be open
Get up
Be up
Close
Be closed
Wake up
Be awake
Begin/start
Be on
Fall asleep
Be asleep
Come
Be here
Lose
Not have
Go
Be there
Join
Be in
Finish
Be over
Leave
Be away
Die
Be dead
Arrive/reach
be
例子：I have bought the bike for two years. (错) 应改为：I have had this bike for two years.
l 现在完成时部分时间状语用法和位置搞错：
Ever曾经，用于肯定句或一般疑问句，放在句中；
Never 从不，带有否定意思，相当于not，放在句中；
Just 刚刚，用于肯定句中，放在句中；
Already已经，用于肯定句中，放在句中；
Yet用于疑问句中是“已经”的意思，用于否定句中是“尚（否定）”的意思，都放在句子末尾
l Now（现在）和just now（刚才）搞错，now用于完成时或现在进行时，just now 用于过去时。
l Have beet to, have gone to, have been in 区别不开。