present perfect

[Offroad]

Please, dear teachers,

could you shed a light on this?

I've seen this film before.
I saw this film in 1990.
I saw this film before.

What have you done with the car keys? I can't find them.
What did you do then? (NOT what have you done then?)

Hey, I lost my keys.
Hey, I have lost my keys.

The cat has eaten your supper. (finished time periods)
The cat ate your supper.
I ate the last of the eggs this morning.

So, teachers, the sentences in blue are right. I wonder if the ones in black are right or not. Present perfect or past simple?

Thanks in advance!

[2006]

Originally Posted by marciobarbalho

Please, dear teachers,

could you shed some light on this?

I've seen this film before.
I saw this film in 1990.
I saw this film before.

What have you done with the car keys? I can't find them.
What did you do then? (NOT what have you done then?)

Hey, I lost my keys.
Hey, I have lost my keys.

The cat has eaten your supper. (finished time periods)
The cat ate your supper.
I ate the last of the eggs this morning.

So, teachers, the sentences in blue are right. I wonder if the ones in black are right or not. Present perfect or past simple?

Thanks in advance!

The sentences in black are correct.

[Offroad]

That's why I dont like studying grammar, too many rules.

1) what's the difference between these sentences?

I've seen this film before.
I saw this film before.

2) Why is this sentence in red wrong?

What did you do then?
What have you done then?

3) What's wrong with the sentence in red?

I have known her for years
I know her for years.

4) American English: Past simple used to give news?

Did you hear? Switzerland declared war on Mongolia!
Have you heard? Switzerland has declared war on Mongolia! (BrE)

Many thanks!

[Dawood Usmani]

[quote=marciobarbalho;395849]That's why I dont like studying grammar, too many rules.

1) what's the difference between these sentences?

I've seen this film before.
I saw this film before.

Dear learner, for making it easier for you to understand it better how Present Perfect Tense is used correctly, I'm giving you the whole usages of Present Perfect with lots of examples. Please read them up carefully. Remember! It'll take you some time to digest them all but I'm sure you'll understand and will be able to clear your concepts.
USE 1 Unspecified Time Before Now


We use the Present Perfect to say that an action happened at an unspecified time before now. The exact time is not important. You CANNOT use the Present Perfect with specific time expressions such as: yesterday, one year ago, last week, when I was a child, when I lived in Japan, at that moment, that day, one day, etc. We CAN use the Present Perfect with unspecific expressions such as: ever, never, once, many times, several times, before, so far, already, yet, etc.
Examples:

• I have seen that movie twenty times.
• I think I have met him once before.
• There have been many earthquakes in California.
• People have traveled to the Moon.
• People have not traveled to Mars.
• Have you read the book yet?
• Nobody has ever climbed that mountain.
• A: Has there ever been a war in the United States?
  B: Yes, there has been a war in the United States.

How Do You Actually Use the Present Perfect?

The concept of "unspecified time" can be very confusing to English learners. It is best to associate Present Perfect with the following topics:
TOPIC 1 Experience

You can use the Present Perfect to describe your experience. It is like saying, "I have the experience of..." You can also use this tense to say that you have never had a certain experience. The Present Perfect is NOT used to describe a specific event.
Examples:

• I have been to France.
  This sentence means that you have had the experience of being in France. Maybe you have been there once, or several times.
• I have been to France three times.
  You can add the number of times at the end of the sentence.
• I have never been to France.
  This sentence means that you have not had the experience of going to France.
• I think I have seen that movie before.
• He has never traveled by train.
• Joan has studied two foreign languages.
• A: Have you ever met him?
  B: No, I have not met him.

TOPIC 2 Change Over Time

We often use the Present Perfect to talk about change that has happened over a period of time.
Examples:

• You have grown since the last time I saw you.
• The government has become more interested in arts education.
• Japanese has become one of the most popular courses at the university since the Asian studies program was established.
• My English has really improved since I moved to Australia.

TOPIC 3 Accomplishments

We often use the Present Perfect to list the accomplishments of individuals and humanity. You cannot mention a specific time.
Examples:

• Man has walked on the Moon.
• Our son has learned how to read.
• Doctors have cured many deadly diseases.
• Scientists have split the atom.

TOPIC 4 An Uncompleted Action You Are Expecting

We often use the Present Perfect to say that an action which we expected has not happened. Using the Present Perfect suggests that we are still waiting for the action to happen.
Examples:

• James has not finished his homework yet.
• Susan hasn't mastered Japanese, but she can communicate.
• Bill has still not arrived.
• The rain hasn't stopped.

TOPIC 5 Multiple Actions at Different Times

We also use the Present Perfect to talk about several different actions which have occurred in the past at different times. Present Perfect suggests the process is not complete and more actions are possible.
Examples:

• The army has attacked that city five times.
• I have had four quizzes and five tests so far this semester.
• We have had many major problems while working on this project.
• She has talked to several specialists about her problem, but nobody knows why she is sick.

Time Expressions with Present Perfect

When we use the Present Perfect it means that something has happened at some point in our lives before now. Remember, the exact time the action happened is not important.

Sometimes, we want to limit the time we are looking in for an experience. We can do this with expressions such as: in the last week, in the last year, this week, this month, so far, up to now, etc.

Examples:

• Have you been to Mexico in the last year?
• I have seen that movie six times in the last month.
• They have had three tests in the last week.
• She graduated from university less than three years ago. She has worked for three different companies so far.
• My car has broken down three times this week.

NOTICE

"Last year" and "in the last year" are very different in meaning. "Last year" means the year before now, and it is considered a specific time which requires Simple Past. "In the last year" means from 365 days ago until now. It is not considered a specific time, so it requires Present Perfect.
Examples:

• I went to Mexico last year.
  I went to Mexico in the calendar year before this one.
• I have been to Mexico in the last year.
  I have been to Mexico at least once at some point between 365 days ago and now.

USE 2 Duration From the Past Until Now (Non-Continuous Verbs)


With Non-Continuous Verbs and non-continuous uses of Mixed Verbs, we use the Present Perfect to show that something started in the past and has continued up until now. "For five minutes," "for two weeks," and "since Tuesday" are all durations which can be used with the Present Perfect.
Examples:

• I have had a cold for two weeks.
• She has been in England for six months.
• Mary has loved chocolate since she was a little girl.

Although the above use of Present Perfect is normally limited to Non-Continuous Verbs and non-continuous uses of Mixed Verbs, the words "live," "work," "teach," and "study" are sometimes used in this way even though they are NOT Non-Continuous Verbs.
ADVERB PLACEMENT

The examples below show the placement for grammar adverbs such as: always, only, never, ever, still, just, etc.
Examples:

• You have only seen that movie one time.
• Have you only seen that movie one time?

2) Why is this sentence in red wrong?

What did you do then?
What have you done then?
(Now, you tell me why the sentence in red is not correct?)

3) What's wrong with the sentence in red?

I have known her for years
I know her for years.
(Now, you should be able to understand on your own why the second sentence in this is wrong. Would you like to tell me why?)

4) American English: Past simple used to give news?

Did you hear? Switzerland declared war on Mongolia!
Have you heard? Switzerland has declared war on Mongolia! (BrE)
Yes, that's true. Americans use this tense to give news or even talk about the recent happenings.

Hope this has helped now .
Dawood

[Offroad]

Originally Posted by dawoodusmani

1) what's the difference between these sentences?

I've seen this film before.
I saw this film before.
I saw this film yesterday.

The second one should be wrong, however, it sounds good, and our colleague has said it is fine. The sentence does not specify any time, 'before' does not make it clear, so, it should be HAVE SEEN, not SAW.



2) Why is this sentence in red wrong?

What did you do then?
What have you done then?

(Now, you tell me why the sentence in red is not correct?)

The second one shall be wrong, the particle then shall mean "at that time", which does not require the present perfect because there's a time specification.



3) What's wrong with the sentence in red?

I have known her for years
I know her for years.

(Now, you should be able to understand on your own why the second sentence in this is wrong. Would you like to tell me why?)

The second one would be right If I write it like this: I know her. But, in that particular case, "for years" suggest the action happened in the past but it's still going on, so, the present perfect is required.



4) American English: Past simple used to give news?

Did you hear? Switzerland declared war on Mongolia!
Have you heard? Switzerland has declared war on Mongolia! (BrE)

Yes, that's true. Americans use this tense to give news or even talk about the recent happenings.



Dawood

OK, Dawood, thank you very much for your help. I'm gonna bookmark this page. But ... if you or a teacher don't mind, I'd like to ask you to have another look at my replies.

Thanks. Very helpful.

[Offroad]

Originally Posted by marciobarbalho

1) what's the difference between these sentences?

I've seen this film before.
I saw this film before.
I saw this film yesterday.

The second one should be wrong, however, it sounds good, and our colleague has said it is fine. The sentence does not specify any time, 'before' does not make it clear, so, it should be HAVE SEEN, not SAW.

Our colleague said it is right and in fact it is if we are thinking of a particular finished time, even if we do not mention it.

I saw this film before. (It was on TV last night)
I've seen this film before. (I can't remember when it was on TV)

Did you see 'Romeo and Juliet'?
Have you seen 'Romeo and Juliet'?

My grandpa did a lot for me. (... when he was alive)
My grandpa has done a lot for me. (... he can't stop hitting on our new 19 years-old neighbour)

4) American English: Past simple used to give news?

Did you hear? Switzerland declared war on Mongolia!
Have you heard? Switzerland has declared war on Mongolia! (BrE)

Yes, that's true. Americans use this tense to give news or even talk about the recent happenings.

I personally never saw this structure before, I believe Americans use both of them

And... PLEASE, I'd like a teacher to have a look at that. I very much appreciate it. Thanks.

[supada]

Thanks to marciobarbalho for your question.

Million thanks to Dawood for your effort.

[Dawood Usmani]

Originally Posted by marciobarbalho

1) what's the difference between these sentences?

I've seen this film before.
I saw this film before.
I saw this film yesterday.

The second one should be wrong, however, it sounds good, and our colleague has said it is fine. The sentence does not specify any time, 'before' does not make it clear, so, it should be HAVE SEEN, not SAW.



2) Why is this sentence in red wrong?

What did you do then?
What have you done then?

(Now, you tell me why the sentence in red is not correct?)

The second one shall be wrong, the particle then shall mean "at that time", which does not require the present perfect because there's a time specification.



3) What's wrong with the sentence in red?

I have known her for years
I know her for years.

(Now, you should be able to understand on your own why the second sentence in this is wrong. Would you like to tell me why?)

The second one would be right If I write it like this: I know her. But, in that particular case, "for years" suggest the action happened in the past but it's still going on, so, the present perfect is required.

OK, Dawood, thank you very much for your help. I'm gonna bookmark this page. But ... if you are a teacher don't mind, I'd like to ask you to have another look at my replies.

Thanks. Very helpful.

I'm gald to see you answers. They are all correct. You're on your road to successes. Keep it up!
Dawood

[David L.]

For all subsequent readers of this thread, you will find this Present Perfect, and as detailed an outline of the other tenses, at

ENGLISH PAGE - Present Perfect

Note the menu at the left-hand side for each of the tenses. Click, and the magic carpet departs.

with additional information at
English Grammar and Writing : English language courses, English Grammar Online

[Dawood Usmani]

Originally Posted by marciobarbalho

Our colleague said it is right and in fact it is if we are thinking of a particular finished time, even if we do not mention it.

I saw this film before. (It was on TV last night)
I've seen this film before. (I can't remember when it was on TV)

The Past Simple indicates that an activity or situation began and ended at a particular time in the past. When we are thinking of a specific time in which an action happened, whether mentioned or unmentioned, we must use Past Simple. The word "before" does not imply a spefified time. Also, this sentence suggests that we have had an experience of seeing this film (before now). It's quite obvious that we must use Present Perfect in this sentence. Your sentence would be fine and make sense if we changed it a bit as " I [also] saw this film yesterday/ two days ago/ when I was in the hospital etc. I regret to say that your colleague is confusing Past Simple with Present Perfect as it's a common practice of learners (including me) and non-native speakers.

Did you see 'Romeo and Juliet'?
Have you seen 'Romeo and Juliet'?

My grandpa did a lot for me. (... when he was alive)
My grandpa has done a lot for me. (... he can't stop hitting on our new 19 years-old neighbour)



I HAVE personally never SEEN this structure before. I believe Americans use both of them. (You are still confusing Present Perfect with Past Simple. I'm amazed! Well, I didn't say that they don't use the present perfect for this. I only said that they also use past simple for this purpose as informed by my American friends.)

And... PLEASE, I'd like a teacher to have a look at that. I very much appreciate it. Thanks.

Hope this has helped more.
Dawood