Since 1990 the global economy has grown more than it did

[aditya8062]

also i quoting one sentence from your manahttan sc book 4 th edition page 249 with the following rule :
the first instance of the verb should usually match the helping verb in the tense .if u need to change tense ,repeat the whole verb in the new tense
wrong : i have never seen as aardvark,but last year my father did .
right :i have never seen as aardvark,but last year my father saw one
can ron plz explain as why this rule is not voilated in the correct option (A ) of the blue queation

thanks and regards

that's not accurate. in fact, one of the prime uses of helping verbs in parallel constructions is to express the same verb in a different tense.

we may already have gotten rid of that "rule" in the 5th edition books. do you have those? if so, is it still there? (i am traveling and don't have the books with me.)
if it's still there, please let us know, so that we can mark it for removal in the next edition. thanks.

Ron i dont have 5 edition sc book and i am not left with much time either ( for the exam )
but plz confirm me on following things :
if i go by your new rule that says : in fact, one of the prime uses of helping verbs in parallel constructions is to express the same verb in a different tense.
then is the following sentence correct? : i have never seen as aardvark,but last year my father did .
i had a feeling that the above mentioned sentence was wrong coz "did" goes with "see" and not "seen" and because the tense mentioned in the sentence is "seen" so "did " is wrong

also if i follow ur new rule then how does it match with the reasoning(i had attached the ur reasoning in my previous post ) that u offered for ruling out option c in the following question :
Soaring television costs accounted for more than half the spending in the presidential campaign of 1992, a greater proportion than it was in any previous election.

A. a greater proportion than it was
B. a greater proportion than
C. a greater proportion than they have been
D. which is greater than was so
E. which is greater than it has been
plz help me ron
thanks and regards

[thanghnvn]

in the video thursday with Ron, name "numeric comparison", the ellipsis is explained. you can find that video.

according that video, A is correct.

pls, see the video and tell me any problem with the vieo.

[ikuta.yamahashi]

also i quoting one sentence from your manahttan sc book 4 th edition page 249 with the following rule :
the first instance of the verb should usually match the helping verb in the tense .if u need to change tense ,repeat the whole verb in the new tense
wrong : i have never seen as aardvark,but last year my father did .
right :i have never seen as aardvark,but last year my father saw one
can ron plz explain as why this rule is not voilated in the correct option (A ) of the blue queation

thanks and regards

that's not accurate. in fact, one of the prime uses of helping verbs in parallel constructions is to express the same verb in a different tense.

we may already have gotten rid of that "rule" in the 5th edition books. do you have those? if so, is it still there? (i am traveling and don't have the books with me.)
if it's still there, please let us know, so that we can mark it for removal in the next edition. thanks.

It seems in 5ed book no change on this statement.
You can use helping verbs to stand for longer verbs or verb phrases.


The first instance of the verb should usually match the helping verb in tense. If you need to change tenses, repeat the whole verb in the new tense.

Wrong: I have never seen an aardvark, but last year my father DID.
Right: I have never seen an aardvark, but last year my father saw one.

[ikuta.yamahashi]

I find another thread from Ron.
very excellent explanation.:)
http://www.beatthegmat.com/helping-verb ... 55384.html

[aditya8062]

@ikuta yamahashi tons of thanks for directing me to that excellent link !!

To Ron : After reading that link i feel that the discrepency that i was observing in these two sentences(that i had asked earlier and i have pasted again down in red colour ) is nothing but its just that helping verb " did " enjoys a kind of exception that helping verb such as "have been" dosent
so for that reason helping verb "did " can be parallel to any tense of an action verb .BUT in case of helping verb "have been" we need to check if omitted/elided words, the EXACT omitted word(s) MUST be present, IN PARALLEL STRUCTURE, elsewhere in the sentence. this means in exactly the same form - no alterations, no tense changes, no nothing

now following the above reasoning i think we can conclude as why "did " is correct in the following sentence
Since 1990 the global economy has grown more than it did during the 10,000 years from the beginning of agriculture to 1950.
AND

why "have been" is wrong in the follwing sentence :

Soaring television costs accounted for more than half the spending in the presidential campaign of 1992,a greater proportion than they have been

Ron kindly confirm if my comprehension of the guideline (at this link http://www.beatthegmat.com/helping-verb ... 55384.html ) is correct ?
thanks and regards
aditya

[RonPurewal]

@ikuta yamahashi tons of thanks for directing me to that excellent link !!

To Ron : After reading that link i feel that the discrepency that i was observing in these two sentences(that i had asked earlier and i have pasted again down in red colour ) is nothing but its just that helping verb " did " enjoys a kind of exception that helping verb such as "have been" dosent
so for that reason helping verb "did " can be parallel to any tense of an action verb .BUT in case of helping verb "have been" we need to check if omitted/elided words, the EXACT omitted word(s) MUST be present, IN PARALLEL STRUCTURE, elsewhere in the sentence. this means in exactly the same form - no alterations, no tense changes, no nothing

now following the above reasoning i think we can conclude as why "did " is correct in the following sentence
Since 1990 the global economy has grown more than it did during the 10,000 years from the beginning of agriculture to 1950.
AND

why "have been" is wrong in the follwing sentence :

Soaring television costs accounted for more than half the spending in the presidential campaign of 1992,a greater proportion than they have been

Ron kindly confirm if my comprehension of the guideline (at this link http://www.beatthegmat.com/helping-verb ... 55384.html ) is correct ?
thanks and regards
aditya

you can understand it in a simpler way, actually -- "have been" isn't a helping verb.

remember, "helping verbs" have to be able to go in front of be, swim, do, etc.
e.g.,
i can swim.
he could do his homework.
etc.
if you look at this pattern, which applies to all helping verbs, you'll notice that "have been" is not a helping verb. (such constructions as have been swim and have been do are not legitimate.)

[aditya8062]

you can understand it in a simpler way, actually -- "have been" isn't a helping verb.

remember, "helping verbs" have to be able to go in front of be, swim, do, etc.
e.g.,
i can swim.
he could do his homework.
etc.
if you look at this pattern, which applies to all helping verbs, you'll notice that "have been" is not a helping verb. (such constructions as have been swim and have been do are not legitimate.)

i am sorry Ron .what i meant in my previous post was for the helping verb "have" (if "have been " is not a helping verb ).will then my analysis in my previous post be correct?
Also the manhattan sc book page 249 edition4 states that helping verb are : "be" ; "do" ; "have"
with all due respect to the defination of helping verb that u have given can u plz tell as how does "have" (the helping verb mentioned in ur book) fits into this defination ?
thanks and regards

[jlucero]

i am sorry Ron .what i meant in my previous post was for the helping verb "have" (if "have been " is not a helping verb ).will then my analysis in my previous post be correct?

You need to be a little bit more clear about your question here as you are referencing things from different posts and forums. Your biggest problem here is that you are focusing on the helper verbs, when really you need to be focusing on the meaning of the sentences and why the helper verbs help to convey a proper meaning. Only when sentences are supposed to be logically parallel do you then need to worry about parallelism:

I have saved (present perfect) money for 10 years and spent (simple past) it all yesterday.

Since 1990 the global economy has grown (present perfect) more than it did (simple past) during the 10,000 years from the beginning of agriculture to 1950.

For this reason, I don't want to logically add a second helper verb, because the tenses don't require it. In your second example:

Soaring television costs accounted (past) for more than half the spending in the presidential campaign of 1992, a greater proportion than they have been (present perfect) in any previous election.

You don't want to compare something that happened in 1992 to something that happened since that time, you are comparing it to previous elections. This is the error in the helper verb.

Also the manhattan sc book page 249 edition4 states that helping verb are : "be" ; "do" ; "have"
with all due respect to the defination of helping verb that u have given can u plz tell as how does "have" (the helping verb mentioned in ur book) fits into this defination ?
thanks and regards

All 3 of those verbs can be used as simple verbs or helper verbs:

I am tall.
I am going to be tall.

I do math.
I do not think that poetry is interesting.

I have money.
I have run five miles.

[southwind288]

Hi Ron

How about B?
Some people said that "from when" is not right.
Can "that" in choice B represents "the growth of the global economy"? Or "that" could only refer to one noun?
Thanks in advance.

you can't use 'that' in this sort of construction, because constructions using 'that of' (or other preposition after 'that') must have EXACTLY parallel structures. in other words, if the second half says 'that during 10,000 years', then the preceding half must say 'the growth of ___ during something else' (or some other time preposition, such as before or after, in place of during).

there's nothing ungrammatical about 'from when', because the clause starting with 'when' is a perfectly legitimate noun clause (i.e., 'when agriculture began' serves as a noun. however:
- it's possible that the gmat does consider such constructions wrong; the only way to tell is to see if they say so in any official answer choices
- regardless of where the gmat stands on the issue, 'the beginning of agriculture' is unquestionably better than 'when agriculture began' (i.e., an actual noun is almost always superior to a circuitous noun clause, when possible)

I don't understand the exact parallel structure:

As you say in here: use-of-as-as-t4211.html

The structure: "The air quality of Las Vegas in 2007 was higher than THAT in 1997 " is still valid???

Please clarify for me

[tim]

What makes you think this construction is invalid? Remember, your goal in sentence correction is not to understand why something is correct, but to understand why all four wrong answer choices are incorrect. If you don't have a solid reason why a particular construction must be incorrect, you need to leave it as an option and accept that it could very well be correct..

[mcmebk]

also i quoting one sentence from your manahttan sc book 4 th edition page 249 with the following rule :
the first instance of the verb should usually match the helping verb in the tense .if u need to change tense ,repeat the whole verb in the new tense
wrong : i have never seen as aardvark,but last year my father did .
right :i have never seen as aardvark,but last year my father saw one
can ron plz explain as why this rule is not voilated in the correct option (A ) of the blue queation

thanks and regards

that's not accurate. in fact, one of the prime uses of helping verbs in parallel constructions is to express the same verb in a different tense.

we may already have gotten rid of that "rule" in the 5th edition books. do you have those? if so, is it still there? (i am traveling and don't have the books with me.)
if it's still there, please let us know, so that we can mark it for removal in the next edition. thanks.

Hi Ron, this rule is still there in the 5th Edition.

Even though you said it is not necessary to use Past Perfect here, it is still very confusing to me... anyway, I think I will just need to remember only to look for verb tense in the very end of POE.

Thank you Ron.

[jlucero]

Probably a good idea for many of us. If you can't find a specific reason to eliminate an answer choice, don't eliminate it. While studying, come back and learn exactly why it's wrong.

[thanghnvn]

Could anyone please explain what's wrong with (C)?

(C) The growth of the global economy since 1990 exceeds that which had been for 10,000 years from the beginning of agriculture

'Had been' seems to point to the time period from beginning of agriculture to 1950 whereas the next time period is from 1990 to present.

Thanks in advance :)

first, you've got a "which" modifier that isn't preceded by a comma, so that's an automatic failure. (note that you can use preposition + which without a comma -- e.g., the box in which you placed your valuables -- but you cannot do so with just plain "which".)

more importantly, "had been" is not parallel to anything in the other half of the sentence; in order to use a parallel structure that contains a form of "to be", you must have another form of "to be" in the other half of the parallel structure.
check out more details here:
http://www.beatthegmat.com/soar-t62473-15.html#280069
(i don't normally cross-post between forums, but that's a very long post that wouldn't make much sense to reproduce here.)

Thank you Ron. From your posting about "which" I understand that

gmat rules that

- only "that" can be used for defining relative clause and no comma precede "that"
- only "comma+which" can be used for non defining relative clause
- "preposition+which" can be used for defining or non defining relative clause. we can use comma or no comma before "preposition+which), denpending on meaning.

is that right? please, confirm

[tim]

Why are you asking us for confirmation? If these are actual rules, you should be able to point to a valid source for the rules. If you cannot point to a valid source, you should not be calling them rules.

[reotokate]

How about B?
Some people said that "from when" is not right.
Can "that" in choice B represents "the growth of the global economy"? Or "that" could only refer to one noun?
Thanks in advance.

you can't use 'that' in this sort of construction, because constructions using 'that of' (or other preposition after 'that') must have EXACTLY parallel structures. in other words, if the second half says 'that during 10,000 years', then the preceding half must say 'the growth of ___ during something else' (or some other time preposition, such as before or after, in place of during).

there's nothing ungrammatical about 'from when', because the clause starting with 'when' is a perfectly legitimate noun clause (i.e., 'when agriculture began' serves as a noun. however:
- it's possible that the gmat does consider such constructions wrong; the only way to tell is to see if they say so in any official answer choices
- regardless of where the gmat stands on the issue, 'the beginning of agriculture' is unquestionably better than 'when agriculture began' (i.e., an actual noun is almost always superior to a circuitous noun clause, when possible)

Hi, so if the question states "the growth of global economy during 1990 & 2000 was more than that during 10,000 yrs,...", this sentence is correct then?

Thank you,