The Acoma and Hopi are probably the two oldest surviving Pueblo commun

Dear Friends,

Here is a detailed explanation to this question-

Meaning is crucial to solving this problem:
Understanding the intended meaning is key to solving this question; the intended meaning of this sentence is that the Acoma and Hopi are probably the two oldest surviving Pueblo communities because they both date back at least a thousand years.

Concepts tested here: Subject-Verb Agreement + Meaning + Modifiers + Verb Forms

• Statements of universal fact are best conveyed through the simple present tense.
• The present perfect tense (marked by the use of the helping verb “has/have”) is used to describe events that concluded in the past but continue to affect the present.
• The introduction of the present participle ("verb+ing"- “dating” in this case) after a comma generally leads to a cause-effect relationship.

A: Correct. This answer choice avoids the subject-verb disagreement seen in Option E, as it uses the present participle ("verb+ing" - "dating" in this sentence) rather than an active verb. Further, Option A uses the phrase "both dating"; the use of the "comma + present participle ("verb+ing" - "dating" in this sentence)" construction conveys the intended meaning - that the Acoma and Hopi are probably the two oldest surviving Pueblo communities because they both date back at least a thousand years; remember, the introduction of the present participle ("verb+ing"- “dating” in this case) after comma generally leads to a cause-effect relationship. Additionally, Option A avoids the tense error seen in Options B and C, as it uses the "comma + present participle ("verb+ing" - "dating" in this sentence)" construction rather than an active verb. Besides, Option A is free of any awkwardness or redundancy.

B: This answer choice alters the meaning of the sentence through the phrase "both of which have dated"; the construction of this phrase incorrectly implies that the Acoma and Hopi are probably the two oldest surviving Pueblo communities, and as a separate action they both date back at least a thousand years; the intended meaning is that the Acoma and Hopi are probably the two oldest surviving Pueblo communities because they both date back at least a thousand years. Further, Option B incorrectly uses the present perfect tense verb "have dated" to refer to a statement of universal fact; remember, statements of universal fact are best conveyed through the simple present tense, and the present perfect tense (marked by the use of the helping verb “has/have”) is used to describe events that concluded in the past but continue to affect the present.

C: This answer choice alters the meaning of the sentence through the phrase "and each has dated"; the construction of this phrase incorrectly implies that the Acoma and Hopi are probably the two oldest surviving Pueblo communities, and as a separate action they both date back at least a thousand years; the intended meaning is that the Acoma and Hopi are probably the two oldest surviving Pueblo communities because they both date back at least a thousand years. Further, Option C incorrectly uses the present perfect tense verb "has dated" to refer to a statement of universal fact; remember, statements of universal fact are best conveyed through the simple present tense, and the present perfect tense (marked by the use of the helping verb “has/have”) is used to describe events that concluded in the past but continue to affect the present.

D: This answer choice alters the meaning of the sentence through the phrase "and each one dating"; the construction of this phrase incorrectly implies that the Acoma and Hopi are probably the two oldest surviving Pueblo communities, and as a separate action they both date back at least a thousand years; the intended meaning is that the Acoma and Hopi are probably the two oldest surviving Pueblo communities because they both date back at least a thousand years.

E: This answer choice incorrectly refers to the singular pronoun phrase "each one" with the plural verb "date". Further, Option E uses the needlessly wordy phrase "each one of which", leading to awkwardness and redundancy.

Hence, A is the best answer choice.

To understand the concept of Simple Tenses" on GMAT, you may want to watch the following video (~2 minutes):



To understand the concept of "Present Perfect Tense" on GMAT, you may want to watch the following video (~2 minutes):



To understand the concept of "Comma Plus Present Participle for Cause-Effect Relationship" on GMAT, you may want to watch the following video (~2 minutes):



All the best!
Experts' Global Team

Option E and D have redundancy problem - Use of 'one' and 'each'

Option B is wordy and awkward 'both of which'

Now between A and C, A looks perfect as it uses correct parallel construction 'surviving' and 'dating'

So the best option is A.

what is the OA?

A for using the right participle -dating -; B and C are out because of using
the perfect tense indicating that the dating back is about to end. The second part of D is a fragment while E has S-V disagreement

A

A. both dating
Use of present participle followed by both is correct.

B. both of which have dated
Present perfect suggests that these communities no longer exist

C. and each has dated
Coordinating conjunction introduces a separate idea rather than modify the communities.
Present perfect suggests that these communities no longer exist

D. and each one dating
Coordinating conjunction introduces a separate idea rather than modify the communities.
A complete clause must be followed by a coordinating conjunction and

E. each one of which date
Subject 'each one of which' is singular.

The Acoma and Hopi are probably the two oldest surviving Pueblo communities, both dating back at least a thousand years.
A. both dating
B. both of which have dated
C. and each has dated
D. and each one dating
E. each one of which date

My doubts:
1) I know that C and D are wrong in part because we need a modiphiyng phrase and not a parallel clause. However, how can be sure that an idea must be subordinated or kept independent from the main clause? For instance, if choice C were "and each is dating", would it be incorrect?
2) I read in other post that B is wrong not only because is wordy but because the tense is wrong. Because the action has concluded in the present and it is not going on. Is it right?, could someone provide a detailed explanation about it?
Thank you!

What is a main factor and what is a subordinate factor? In the given case, the text wants to establish that the two sites are examples of the oldest communities; in proof of that, it gives the dating data. Therefore, the data are additional facts and supportive ideas to the main theme of oldness. Putting them on equal footing with the main clause using a co-ordinate conjunction namely ‘and’ will end up in alteration of intent. Hence, C and D are wrong. Even if C were to be amended grammatically as has been stated by metallicafan, it would not make an ideal choice as far as meaning is concerned.

B is wrong because, when you use the present perfect, you are trying to imply that both are doing the dating themselves and that the effect of dating is no more. The effect of dating namely that they are part of the oldest communities is going to be there forever and a universal fact. Therefore, we need to use a simple present tense to express such a feeling.

Though the answer has been given, I just want to share my part of discussion. Before advancing, many thanks to metallicafan for the question.
My take:
Always remember, there are two requirements of COMMA + ING construction:
a) it should be adverbial, modifying the entire previous clause
b) it should be attributed to the subject of the previous clause.

The options C and D neither explain the preceding clause nor become a consequential effect.
Same goes for e as well.
Now when we move to B, here we see a change of tense which is nog required at all, in fact is incorrect.
Hence A.

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The Acoma and Hopi are probably the two oldest surviving Pueblo communities, both dating back at least a thousand years.

A. both dating
Correct. Verb-ing modifier + comma --> modifies a preceding clause.==> "dating" is verb-ing modifier that provides more information for the preceding clause (why Acoma & Hopi are the oldest surviving Pueblo communities).

B. both of which have dated
Wrong. "which" should modifies the closest noun --> "which" modifies "communities", not "Acoma & Hopi" --> Wrong.

C. and each has dated
Wrong. "each" of communities or "each" of "Acoma & Hopi"??? --> Very obscure.

D. and each one dating
Wrong. Same error as in C. "each" of communities or "each" of "Acoma & Hopi"??? --> Very obscure.

E. each one of which date
Wrong. Same error as in B. "which" should modifies the closest noun --> "which" modifies "communities", not "Acoma & Hopi" --> Wrong.

Hope it helps.

E is a simple subject-verb issue. It should be each . . . dates.

In B, "have dated" doesn't make sense. Dating in this sense is not something they have actually done. It's just a way of describing how old they are. We'd say "This legend dates back to the 12th century," not "This legend has dated back to the 12th century." (This issue also rules out C, with "has dated.")

D is just not a sentence. It links a modifier to the main clause with "and," and that doesn't work.

From Ron (Manhattan Prep): https://www.manhattanprep.com/gmat/foru ... t9670.html



GMATNinja & GMATNinjaTwo Could you help to explain "VERBing - dating" in this problem? Why "dating" is placed after the pronoun "both"? What is being modified here?

The -ing modifier ("dating") modifies "communities" -- and the adverb "both" modifies "dating." In other words, both the Acoma community and the Hopi community date back at least a thousand years, and the word placement isn't a problem at all.

Hi GMATNinja,

Can you please explain why the tense used is incorrect here? My understanding about present perfect tense is - An action that begins in the past and continues to the present. But in the explanation given above its mentioned that '"has dated" implies that this is not the case anymore (this particular construction really only makes sense in the present tense -- or as an -ing modifier attached to a present-tense clause, since -ing modifiers adopt the tense of the clause to which they are attached.)'.

Hello hazelnut,


Although your question has already been answered, I would like to present to you how at e-GMAT we treat the modifier both dating back at least a thousand years.

We call this modifier Noun + Noun Modifier in which both = Noun and dating back at least a thousand years = Noun Modifier. Well, technically both is a pronoun. But since it refers to a noun entity, it is used in the Noun + Noun Modifier structure in the place of Noun as we see in this official sentence.

A Noun + Noun Modifier can modify any noun in the preceding clause or even the entire preceding. The modification by this modifier depends upon the context of the sentence.

In this official sentence, the Noun + Noun Modifier both dating back at least a thousand years modifies the noun The Acoma and Hopi.

For all the details, explanations, and examples (official sentences included) pertaining to the Noun + Noun Modifiers, please review our article named Noun + Noun Modifiers: The most "versatile" modifier in the following link:

https://gmatclub.com/forum/noun-noun-modifiers-the-most-versatile-modifier-137292.html


Hope this helps.
Thanks.
Shraddha

Hello Vyshak,

I would like to help you resolve your doubt.

The Acoma and Hopi are probably the two oldest surviving Pueblo communities, both dating back at least a thousand years.


It is a general fact about the two communities mentioned in the official sentence above that these communities are at least a thousand years old, a fact that cannot be changed or will not remain true in the time to come. Hence, this fact must be written either in simple present tense verb or in the form of verb-ing modifier as we in this sentence.

When an event is written in present perfect tense, it denotes that the event may change in the future.

We say: Sun rises in the east because this fact is never going to change. If we say: Sun has risen in the east, the sentence will mean that in present the Sun is rising in the east. But in future it may not do so.

For this reason, usage of has dated back (present perfect tense) does not work in the context pf this official sentence.


Hope this helps.
Thanks.
Shraddha

Hello arvind910619,


I would like to help you resolve your doubt.

Let's take a look at the sentence with Choice D inserted in it.

The Acoma and Hopi are probably the two oldest surviving Pueblo communities, and each one dating back at least a thousand years.


Even if we remove one from the above mentioned sentence, it will stand incorrect because and is preceded by a comma. This means that we need an independent clause after comma + and. But there is no verb for the subject each as dating cannot act as verb as it is not preceded by any helping verb such is/was etc. Hence, this choice is incorrect.


Hope this helps.
Thanks.
Shraddha

Hi Vyshak, the issue is not as much of tense as of voice.

B says that both communities have dated. This is active voice.

This is incorrect because the communities cannot date themselves; clearly, someone else has dated them.

So, the correct usage would be the one using passive voice: both of which have been dated

I disagree.

date back to can be used both actively and passively.

An example from Collins:

The brooch dates back to the fourth century BC.