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:

this morning, tonight,this April, now, once，before, already, recently，lately

现在完成时的时间状语

for, since, so far, ever, never, just, yet, till / until, up to now, in past years, always,

不确定的时间状语

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

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

举例：

I saw this film yesterday.

I have seen this film.

Why did you get up so early?

Who hasn t handed in his paper?

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.

He has been a League member for three years.

He joined the League three years ago.

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时，不能使用现在完成时，要用过去时。

Tom has written a letter to his parents last night.

Tom wrote a letter to his parents last night.

1)It is the first / second time . that 结构中的从句部分，用现在完成时。

It is the first time that I have visited the city.

It was the third time that the boy had been late.

2)This is the that 结构，that 从句要用现在完成时.

This is the best film that I ve seen.

这是我看过的最好的电影。

This is the first time I ve heard him sing. 这是我第一次听他唱歌。

典型例题

---Do you know our town at all?

---No, this is the first time I ___ here.

A. was B. have been C. came D. am coming

答案B. This is the first time 后面所加从句应为现在完成时，故选B。

---Have you ____ been to our town before?

---No, it s the first time I ___ here.

A. even, come B. even, have come C. ever, come D. ever, have come

答案D. ever意为曾经或无论何时，反意词为never，此两词常用于完成时。 This is the largest fish I have ever seen. It is / was the first time +that-clause 的句型中，从句要用完成时。

注意：非延续性动词的否定形式可以与表示延续时间的状语连用。即动作不发生的状态是可以持续的。

I have received his letter for a month.

I haven t received his letter for almost a month.

Since 用来说明动作起始时间，for用来说明动作延续时间长度。

I have lived here for more than twenty years.

I have lived here since I was born..

My aunt has worked in a clinic since 1949.

Some new oilfields have been opened up since 1976.

I have known Xiao Li since she was a little girl.

My brother has been in the Youth League for two years.

I have not heard from my uncle for a long time.

注意：并非有for 作为时间状语的句子都用现在完成时。

I worked here for more than twenty years.

I have worked here for many years.

小窍门： 当现在完成时+一段时间，这一结构中，我们用下面的公式转化，很容易就能排除非延续动词在完成时中的误使。

1) Tom has studied Russian for three years.

= Tom began to study Russian three years ago, and is still studying it now.

2) Harry has got married for six years.

= Harry began to get married six years ago, and is still getting married now.

显然，第二句不对，它应改为 Harry got married six years ago. 或 Harry has been married for six years.

1) since +过去一个时间点 。

I have been here since 1989.

2) since +一段时间+ ago

I have been here since five months ago.

3) since +从

查阅未显示的内容点击这里