The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.
A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding
I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:
has expanded --> present perfect simple
has been expanding --> present perfect continuous
Can somebody explain, why the present perfect simple is incorrect here?
thx a lot!
present perfect simple vs. present perfect continuous
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has expanded means that the universe is no more expanding........it has reached to it's last stage of expansion recently ................ in the above sentence has expandedis not required as it's a true fact that the universe is still expanding.......Fractal wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.
A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding
I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:
has expanded --> present perfect simple
has been expanding --> present perfect continuous
Can somebody explain, why the present perfect simple is incorrect here?
thx a lot!
I hope I make sense
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mhh but "has expanded" is present perfect, so it is used for a action happend in the past and still continues in the present.... ?! so the universe could still be expanding then... ?aspirant2011 wrote:has expanded means that the universe is no more expanding........it has reached to it's last stage of expansion recently ................ in the above sentence has expandedis not required as it's a true fact that the universe is still expanding.......Fractal wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.
A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding
I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:
has expanded --> present perfect simple
has been expanding --> present perfect continuous
Can somebody explain, why the present perfect simple is incorrect here?
thx a lot!
I hope I make sense
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expanded is past form of the verb which has got completed........when we add has in front of it then it means that the action started in the past and has recently got completed whereas expanding is the continous form of the verb i.e which is still happening & when we add has in front of it then it means that the action started in the past and is still happeningFractal wrote:mhh but "has expanded" is present perfect, so it is used for a action happend in the past and still continues in the present.... ?! so the universe could still be expanding then... ?aspirant2011 wrote:has expanded means that the universe is no more expanding........it has reached to it's last stage of expansion recently ................ in the above sentence has expandedis not required as it's a true fact that the universe is still expanding.......Fractal wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.
A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding
I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:
has expanded --> present perfect simple
has been expanding --> present perfect continuous
Can somebody explain, why the present perfect simple is incorrect here?
thx a lot!
I hope I make sense
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what about "i haven written 4 books" --> this sentence doesn't mean, that i will not write any more books in the future...aspirant2011 wrote:expanded is past form of the verb which has got completed........when we add has in front of it then it means that the action started in the past and has recently got completed whereas expanding is the continous form of the verb i.e which is still happening & when we add has in front of it then it means that the action started in the past and is still happeningFractal wrote:mhh but "has expanded" is present perfect, so it is used for a action happend in the past and still continues in the present.... ?! so the universe could still be expanding then... ?aspirant2011 wrote:has expanded means that the universe is no more expanding........it has reached to it's last stage of expansion recently ................ in the above sentence has expandedis not required as it's a true fact that the universe is still expanding.......Fractal wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.
A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding
I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:
has expanded --> present perfect simple
has been expanding --> present perfect continuous
Can somebody explain, why the present perfect simple is incorrect here?
thx a lot!
I hope I make sense
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the sentence means that till yet I have written 4 books............it doesn't convey anything about future actionsFractal wrote:what about "i haven written 4 books" --> this sentence doesn't mean, that i will not write any more books in the future...aspirant2011 wrote:expanded is past form of the verb which has got completed........when we add has in front of it then it means that the action started in the past and has recently got completed whereas expanding is the continous form of the verb i.e which is still happening & when we add has in front of it then it means that the action started in the past and is still happeningFractal wrote:mhh but "has expanded" is present perfect, so it is used for a action happend in the past and still continues in the present.... ?! so the universe could still be expanding then... ?aspirant2011 wrote:has expanded means that the universe is no more expanding........it has reached to it's last stage of expansion recently ................ in the above sentence has expandedis not required as it's a true fact that the universe is still expanding.......Fractal wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.
A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding
I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:
has expanded --> present perfect simple
has been expanding --> present perfect continuous
Can somebody explain, why the present perfect simple is incorrect here?
thx a lot!
I hope I make sense
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point is that
has/have are used for present tense, present perfect/present continous
will,shall are used when refering to future
In the above sentence I have written 4 books means we are refering to present tense out here i.e till date I have written 4 books..............the sentence doesn't mention anything about future i.e whether I will write more books or blah blaah blaaah
hope it clears.......
has/have are used for present tense, present perfect/present continous
will,shall are used when refering to future
In the above sentence I have written 4 books means we are refering to present tense out here i.e till date I have written 4 books..............the sentence doesn't mention anything about future i.e whether I will write more books or blah blaah blaaah
hope it clears.......
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C - In addition to tense error, there is no 'and'.Fractal wrote:The widely accepted big-bang theory holds that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding ever since.
A. that the universe began in an explosive instant 10 to 20 billion years ago and has been expanding
B. that the universe had begun in an explosive instant 10 to 20 billion years ago and had been expanding
C. that the beginning of the universe was an explosive instant 10 to 20 billion years ago that has expanded
D. the beginning of the universe to have been an explosive instant 10 to 20 billion years ago that is expanding
E. the universe to have begun in an explosive instant 10 to 20 billion years ago and has been expanding
I don't understand, why "has expanded" is incorrect and "has been expanding" is correct. As far as I know, these two forms are both Present Perfect:
has expanded --> present perfect simple
has been expanding --> present perfect continuous
Can somebody explain, why the present perfect simple is incorrect here?
thx a lot!
He has visited USA. It conveys 2 things:
1) He has visited USA before current time and is still there
2) he has visited USA before current time and the effect is still true (for example, he has returned but he has not yet opened his bags)
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- Whitney Garner
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Let's see if we can clear up the uses for Present Perfect and Present Perfect Continuous a bit more thenFractal wrote:i don't really get the point, but thx anyway
Present Perfect
Form:
[has/have + past participle]
We have eaten dinner. (positive)
She has not traveled there. (negative)
Has he seen the movie? (question)
Uses:
**(simple) Present Perfect is used to talk about things that happened at an unspecified time before Now: we DO NOT use Present Perfect with specific time expressions (yesterday, last week, one day, etc.) but we CAN use it with relative time expressions (ever, never, once, before, etc). All you are trying to do is say that something happened at some point in time before now. "No one has ever seen this before" or "I have met the professor"
(a) When talking about Experience or a Quality that is true about something (not the specific event). "I have been to Spain", "Si has studied English", etc.
(b) When saying something has changed over time. "You have grown since I last saw you", "My grammar has improved since starting this class", etc.
(c) An accomplishment: "Scientists have discovered many new planets", "My mom has learned how to program the DVR", etc.
(d) Something NOT complete but that you are expecting: "We have not eaten dinner yet", "The printer has had many issues completing the job", etc.
**So, Simple Present Perfect is just saying something happened before but we're not being terribly specific about when. If I want to use a specific time, I need to use simple past:
[INCORRECT] "I have been to Texas last year"
[CORRECT] "I went to Texas last year"
[CORRECT] "I have been to Texas in the last year" (meaning I have been at least once in the last year, but not being specific about how many times or exactly when)
------- Now to Continuous... -------
Present Perfect Continuous
Form:
[has/have + BEEN + present participle]
I have been reading. (positive)
They have not been eating. (negative)
Has he been listening? (question)
Uses:
There are 2 specific uses for the Present Perfect Continuous form of a verb:
(1) The action Started in the past and continues up to this moment:
- "She has been teaching for the past 15 years" (she is still teaching)
- "They have been waiting for a table for hours" (they are still waiting)
(2) Something occurred very recently (and we typically note that in the sentence):
- "He has been feeling sick lately"
- "I have been practicing grammar a lot recently"
So think about a quick comparison:
"She has taught since August" vs "She has been teaching since August"
The first expression indicates that she has had the quality of teaching or being a teacher since August - so she started as a teacher in August. The second implies that she has been teaching the entire time from August until now - she may have been a teacher much longer than that - this is just a current stretch of actual teaching.
I know that these concepts can inter-mingle, but just think of it this way:
- If I use the past participle (typically -ed), then I mean for something to have happened in the general/non-specific past and be done, but I can still use it to define some quality in myself. If I say "I have eaten a hot dog" it means that at some point in my past, I ate a hot dog and now I can forever say that it is something I did.
- If I use the present participle (typically -ing), it means the action carries right up to the present moment and has an ongoing feel to it. "I have been eating a hot dog" means that I started eating it sometime before this moment BUT I am still eating it.
- And if I want to talk about an event that happened in the past and be very specific about when it happened, I would use simple Past: "We learned to conjugate verbs yesterday", "When I was 6, I started first grade."
Whit
Whitney Garner
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Manhattan Prep
Contributor to Beat The GMAT!
Math is a lot like love - a simple idea that can easily get complicated
GMAT Instructor & Instructor Developer
Manhattan Prep
Contributor to Beat The GMAT!
Math is a lot like love - a simple idea that can easily get complicated
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hi Whitney i appreciate your detailed explanation but i don't agree to some part of it. Are you sure in saying that "i have eaten a hot dog" is a past event? its still Present perfect tense. the action has to continue till present. how can you be so sure it got over??
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Be careful - what I am saying is that the event happened SOME TIME in the past, but I have not given any indication as to when. And the Past Perfect tense lets me know that the action has been completed. "I have eaten a hot dog" means that at some point before right this second, I consumed a hot dog - but I am not giving any more detail other than that. If I want to show that I am still in the process of eating the hot dog (but I started eating it in the past), I would say "I have been eating a hot dog dog..."force5 wrote:hi Whitney i appreciate your detailed explanation but i don't agree to some part of it. Are you sure in saying that "i have eaten a hot dog" is a past event? its still Present perfect tense. the action has to continue till present. how can you be so sure it got over??
You can be sure that the event is complete BECAUSE I used Past Perfect and NOT Past Perfect Continuous.
When I said that you can use Past Perfect to describe actions that have some permanence (meaning that they still apply to me now), I meant that I can use it to describe something that now defines me. For example - "I have eaten a hot dog" describes me now. Because there was a point sometime in my past that I consumed a hot dog, I can now always say that about myself. For example, imagine a marathon.
(a) "I have run a marathon."
(b) "I ran a marathon"
(c) "I have been running a marathon."
(a) At some point in my past I started and finished a marathon. Now I can go around and brag to my friends that I am a person who has ever run a marathon - it is a quality about me now!
(b) I would use this to tell someone that at some point in the past, I started and finished a marathon. Using this simple past, I would likely be more specific about the time: ie. I ran a marathon yesterday (or last week)
(c) I would say this if I was just recently running the marathon and maybe just finished (ie. "Why didn't you answer the phone on the first ring??" "Sorry, I have been running a marathon") - so maybe I just stopped or I could still be running ("I have been running a marathon for the past 3 hours, and I'm exhausted and would like to quit!!")
Whit
Whitney Garner
GMAT Instructor & Instructor Developer
Manhattan Prep
Contributor to Beat The GMAT!
Math is a lot like love - a simple idea that can easily get complicated
GMAT Instructor & Instructor Developer
Manhattan Prep
Contributor to Beat The GMAT!
Math is a lot like love - a simple idea that can easily get complicated