完成时与过去时的区别

比较过去时与现在完成时

1）过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。

2）过去时常与具体的时间状语连用，而现在完成时通常与模糊的时间状语连用，或无时间状语。

一般过去时的时间状语:

yesterday, last week，…ago, in1980, in October, just now, 具体的时间状语

共同的时间状语:

，latelybefore, already, recentlythis morning, tonight,this April, now, once，

现在完成时的时间状语till / until, up to now, in past years, always, for, since, so far, ever, never, just, yet, 不确定的时间状语

live, teach, learn, 动词一般是延续性的，如）3现在完成时可表示持续到现在的动作或状态，work, study, know.

等。come, go, leave, start, die, finish, become, get married 过去时常用的非持续性动词有举例：

I saw this film yesterday.

（强调看的动作发生过了。）

I have seen this film.

（强调对现在的影响，电影的内容已经知道了。）

Why did you get up so early？

（强调起床的动作已发生过了。）

Who hasn't handed in his paper

（强调有卷子，可能为不公平竞争。）

She has returned from Paris.

她已从巴黎回来了。

She returned yesterday.

她是昨天回来了。

He has been in the League for three years.

(在团内的状态可延续)

He has been a League member for three years.

(是团员的状态可持续)

He joined the League three years ago.

( 三年前入团，joined为短暂行为。)

I have finished my homework now.

---Will somebody go and get Dr. White？

---He's already been sent for.

句子中如有过去时的时间副词（如yesterday, last, week, in 1960）时，不能使用现在完成时，要用过去时。

（错）Tom has written a letter to his parents last night.

（对）Tom wrote a letter to his parents last night.

精讲现在完成时

现在完成时是初中英语教学中的一个重点，也是一个难点，在学习中应注意以下几点：

一、现在完成时与一般过去时的区别

1.现在完成时强调过去发生的动作对现在造成的影响，而一般过去时不强调过去的动作与现在的关系。如：

I have lost my pen.(强调我现在没有笔)

I lost my pen.(过去笔掉了，没说明现在是否有笔)

2.现在完成时不可和表过去的时间状语连用(before,just等除外)，但一般过去时可和表过去的时间状语，如yesterday,last week,three days ago,just now等连用。如：

A：Hello,Kate!Have you had supper？

B：Yes,I have.

A：When did you have it？

在此例中，应注意When是一个不确定的过去时间。

二、for和since的运用

for表“经历(一段时间)”，而since表“自从……以来”。常见结构：for＋一段时间；since＋一段时间＋ago;since ＋一个时间点；since＋从句。如：

has stayed here for 3 hours.

has stayed here since 3 hours ago.

has stayed here since 3 o'clock.

has taught English since he came here.

三、短暂性动词通常不能和表一段的时间状语连用，应用意义与其相近的延续性动词、be＋形容词/副词等来代替他们。如：borrow改为keep/have;die改为be dead;leave改为be away等，或将完成时改为一般过去时。如：

1.错：He has died for 3 years.

正：He has been dead for 3 years.

正：He died 3 years ago.

2.错：How long have you borrowed it？

正：How long have you kept it？

在例2中应注意how long是一个不确定的一段时间。但应注意，短暂性动词的否定式表示一个状态，它可以和表一段的时间状语连用。如：

I haven't seen you for 2 years.

四、have(has)been 与have(has)gone的区别

have(has)been表“到过某地”；have(has)gone表“已去”。如：

A：Where is Li Lei？

B：He has gone to the library.

通过A的问话，说明Li Lei不在说话处，所以这儿应回答“他去了……”。

五、already和yet的区别

already常用于肯定句中或句末；yet常用于一般疑问句或否定句末。但表惊讶时already也可用于疑问句。如：

has already finished his homework.

2. Tom hasn't finished his homework yet