A 1972 agreement between Canada and the United States reduced

I picked D as it better follows the intent of the sentence...

"agreement reduced the amount that the municipalities are allowed to dump"....that the agreement refers to dumping that is ongoing is best expressed here.

"agreement reduced the amount that the municipalities had been allowed to dump" the agreement could not really have reduced the amount that had already been dumped, right?

The bottom-line here is - Which is the correct usage- a) Had been allowed to dump or b) were allowed to dump or C) are allowed to dump.

To understand the concept better, let’s delve into some definitions.

A present tense is used for a current activity or a daily activity or a universal activity.

A past tense used for an activity that started in the past and “ended” in the past. “Ending” in the past is an essential ingredient of past tense. If it had not ended and if it is still continuing, then we can not use the past and we have to use present perfect.

A past perfect is required to be used for distinguishing between two past tense events. The basic requirements are that both the events should have started and “ended” in the past; secondly one of the events should have ended distinctly earlier than the other event.

Given this backdrop, let us analyze the given choices. Has the dumping ended on the date of the agreement in 1972? The dumping had ended neither before nor after the date of the agreement.

Since the ending element is absent in the context, use of either past perfect or past tense is inappropriate.

You can perfectly use a present perfect, which is what Choice C is doing but unfortunately that choice suffers other anomalies such as “reduces” and “phosphate amount”.

D has no such infringements and hence the right choice.

There was a remark that Choice E is a fragment. A fragment lacks a verb. But the choice has ‘reduces’ as the main verb. Hence it is not a fragment, although it is still not the correct answer for using the present tense “reduces”

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 core meaning of the sentence is that a 1972 agreement between Canada and the United States reduced the amount of phosphates that municipalities are allowed to dump into the Great Lakes.

Concepts tested here: Tenses + Meaning

• The simple present tense is used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature.
• The simple past tense is used to refer to events that concluded in the past.
• The past perfect tense (marked by the use of the helping verb "had") is used when a sentence contains two actions in the past; the helping verb "had" is used with the action in the "greater past".
• The past perfect continuous tense (marked by the use of helping verb "had/have been") is used when a sentence contains two actions in past and one action is in greater past as well as continuous in nature; the helping verb "had been" is used with the action that is in the greater past and continuous in nature.
• The present perfect continuous tense (marked by "has/have been") is the correct tense to refer to actions that started in past and continue into the present.
• For referring to the purpose or intent of an action, the infinitive verb form (“to + base form of verb"- "to + dump" in this sentence) is preferred over the present participle ("verb+ing" - "dumping" in this sentence) construction.

A: Trap. This answer choice incorrectly uses the past perfect tense verb “had been allowed” to refer to an action taking place in the current time frame; please remember, the simple present tense is used to refer to actions taking place in the current time frame, and the past perfect tense (marked by the use of helping verb "had") is used when a sentence contains two actions in the past; the helping verb "had" is used with the action in the "greater past".

B: This answer choice incorrectly uses the past perfect continuous tense verb “had been dumping” to refer to an action taking place in the current time frame; please remember, the simple present tense is used to refer to actions taking place in the current time frame, and the past perfect continuous tense (marked by the use of helping verb "had/have been") is only used when a sentence contains two actions in past and one action is in greater past as well as continuous in nature. Further, Option B alters the meaning of the sentence through the phrase “municipalities had been dumping”; the construction of this phrase incorrectly implies that the 1972 agreement reduced the amount of phosphates that municipalities had practically been dumping into the Great Lakes; the intended meaning is that the 1972 agreement reduced the amount of phosphates that municipalities are permitted to dump into the Great Lakes.

C: This answer choice incorrectly uses the simple present tense verb “reduces” to refer to an action that concluded in the past; please remember, the simple past tense is used to refer to actions that concluded in the past, and the simple present tense is only used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature. Further, Option C incorrectly uses the present perfect continuous tense verb “have been allowed to dump” to refer to an action taking place in the current time frame; please remember, the simple present tense is used to refer to actions taking place in the current time frame, and the present perfect continuous tense (marked by "has/have been") is the correct tense to refer to actions that started in past and continue into the present.

D: Correct. This answer choice correctly uses the simple past tense verb “reduced” to refer to an action that concluded in the past. Further, Option E correctly uses the simple present tense verb “are allowed” to refer to an action taking place in the current time frame. Moreover, Option D uses the phrase “are allowed to dump”, conveying the intended meaning – that the 1972 agreement reduced the amount of phosphates that municipalities are permitted to dump into the Great Lakes. Additionally, Option E uses the infinitive verb form (“to + base form of verb"- "to + dump" in this sentence) to refer to the intent of the action “allowed”.

E: This answer choice incorrectly uses the simple present tense verb “reduces” to refer to an action that concluded in the past; please remember, the simple past tense is used to refer to actions that concluded in the past, and the simple present tense is only used to indicate actions taking place in the current time frame, indicate habitual actions, state universal truths, and convey information that is permanent in nature. Further, Option E uses the present participle ("verb+ing" - "dumping" in this sentence) construction to refer to the intent of the action “allowed”; please remember, for referring to the purpose or intent of an action, the infinitive verb form (“to + base form of verb") is preferred over the present participle ("verb+ing" - "dumping" in this sentence) construction.

Hence, D is the best answer choice.

Additional Note: Please note that the verb construction "had been allowed", used in Option A, is the passive version of the past perfect tense construction "had allowed", not a past perfect continuous tense verb.

To understand the concept of "Simple Tenses" on GMAT, you may want to watch the following video (~1 minute):



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



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



All the best!
Experts' Global Team

D it is.
Past perfect is used to suggest that something is over and done with before the main action of the past. It would be OK to say:

The 1972 agreement replaced the amount of phosphates that had been allowed with a new amount.

But if you are talking about changing an amount, then the amount existed before and continues to exist after the 1972 agreement. The present tense is used to refer to something that exists for all time.

Copernicus revealed that the Earth and the planets all revolve around the Sun.

"Revolve" is in the present tense because it is an action that was then and continues to take place. It would be wrong to say: "...revealed that the Earth and the planets revolved..." or "had revolved."

In the sentence under dicussion, there was and continues to be an amount of phosphates that municipalities can dump. The 1972 agreement reduced the amount, but the amount continues to exist.

I'll try one more example. Suppose I started a new diet last week. I formerly ate all the red meat I wanted. Under the new diet I allow myself to eat only 100 grams a day.

The diet I started last week reduced the amount of red meat I am allowed to eat to 100 grams a day.
It would be wrong to say:

The diet I started last week reduced the amount of red meat I had been allowed to eat to 100 grams a day.


Explanation by 800BOB.(testmagic)
HTH

The gist of the sentence boils down to the restriction the agreement imposed on future action rather than on past action. Obliviously the agreement can't ask those who exceeded the dumping limits prior to 1972, to recover the dumped material from the lakes. So any mention of past tense or past perfect for describing the dumping is null and void. Choices A and B will be incorrect for this reason.

Since it is an agreement that was mooted in 1972, we are required to use past tense to denote the main verb. So C and E which use the present tense verb reduces can be eliminated.

D for using the past tense reduce to expose the timing of the event, and the present tense for some thing the is currently in vogue and that which is going to continue in the future, is the preferred choice.

Hi All,
A 1972 agreement between Canada and the United States reduced the amount of phosphate that municipalities had been allowed to dump into the Great Lakes.



The intended meaning of the sentence is that till 1972, municipalities were allowed to dump a certain amount of phosphate into the Great Lakes. However, a 1972 agreement between Canada and the US reduced this amount.



The only error in this sentence is the use of past perfect tense “had been allowed”. Let us understand how. Per the sentence, the agreement reduced the amount that municipalities were allowed to dump. Now in this sentence, the verb tense - past perfect tense - had been allowed - is incorrect because it non-sensically implies that municipalities were allowed to dump a certain amount sometime in the past - (they are no longer allowed to dump now, since the action is already completed) and then the next event in the past happened - the agreement reduced this amount. It is not possible to reduce an amount for something that has already happened (had been allowed).

Process of Elimination

Choice A: Incorrect for the reason discussed above.

Choice B: reduced the phosphate amount that municipalities had been dumping. Incorrect. Per this choice the agreement itself did the action of "reduce". This cannot be true because the agreement cannot reduce the amount of phosphates dumped by municipalities. The agreement can only provide limits for this amount. The municipalities have to then take appropriate actions to reduce their emissions to meet the new allowable limits. Removal of “allow” distorts the meaning of the sentence. Also, this choice has the same verb tense issue as in choice A.

Choice C: reduces the phosphate amount municipalities have been allowed to dump. Incorrect. Since agreement took place in 1972, use of present tense “reduces” is incorrect. Also, this sentence states a general fact about the amount of phosphate the municipalities are allowed to dump. This must be stated in the simple present tense. Use of present perfect tense “have been allowed” to state a general fact is not correct.

Choice D: reduced the amount of phosphates that municipalities are allowed to dump. Correct. This choice conveys the intended meaning. In general, the municipalities are allowed to dump a certain amount of phosphate. However, an agreement between Canada and the US reduced that amount in 1972.

Choice E: reduces the amount of phosphates allowed for dumping by municipalities. Incorrect. This choice has the same verb tense error as in choice C. Use of “for” after “allowed” is unidiomatic.



1. Understand the intended meaning of the sentence.
2. Past perfect tense denotes that the action is already over.
3. Be careful of the choices that remove certain words present in the original choice. Such removals may change the meaning of the sentence.

Hope this helps.
Thanks.
Shraddha

Hey guys,

Interesting debate - with verb tense errors I firmly believe that logic plays a huge role in your ability to make tough decisions. When looking at the choices, ask yourself "is it possible the events happened in this order?".

Here, is it possible that this law reduced "the amount that municipalities (PREVIOUSLY) had been able to dump"? Remember, "had been" means "before the past-tense event". A law can't retroactively change something like an amount - whatever these cities dumped is already dumped. so "had been" logically doesn't make sense for any of these.

The fact that we're anchored in 1972 at the beginning of the sentence means that we're stuck with the past-tense "reduced" and not "reduces", so that narrows us down to D, the only choice that sets a logical timeline for these events.

There's no doubt about the OA: it is definitely D, and there is nothing wrong with this question (which really is an official GMAT question).

People get confused by this one because of the shifts in time. An agreement that took place in the past (described correctly in the past tense) had an effect on what we are now allowed to do (described correctly in the present tense). Similarly, I could say that a movie made in 1950 "changed the way that we see romantic love" or that a change made to the tax code in 1985 "limits the amount of losses one is able to deduct."

A is absolutely wrong. There's no ambiguity about that either. It starts in past tense and shifts to past perfect. This implies that the law worked backwards in time , changing the amount that people had been allowed to dump before the law was passed! Can we all agree that that makes no sense? Remember that the past perfect ("had been") is only used to describe events that precede some other past event in the sentence (or--outside the GMAT--elsewhere in the text). Answer choice A has only one past event, so the absurd interpretation I've provided is actually the only possible meaning! That choice has to go.

Hi Ergenekon, I don't take that for an answer, because I am a non-native speaker too:).

Let's give it another shot, with a fresh example, that you can better associate with.

Prior to 2012, GMAT used to have two essays as part of AWA. In 2012 however, GMAC introduced the IR section, replacing one of the AWA essays. So:

i) Prior to 2012, GMAT had two essays as part of AWA
ii) Since 2012, GMAT has had one essay as part of AWA.

How would we articulate this in a sentence?

A 2012 change in the pattern of GMAT reduced the number of essays that students are asked to attempt as part of the GMAT exam.

Now, why can’t we articulate the sentence as:

A 2012 change in the pattern of GMAT reduced the number of essays that students had been asked to attempt as part of the GMAT exam.

For this, let’s understand the intent of the sentence. Students are asked to attempt what as part of the GMAT exam? Well, students are asked to attempt essays as part of the GMAT exam. So, that (in that students…) is clearly referring to essays (and not to number of essays).

Summarily, students attempted essays even prior to 2012; students attempt essays even now (and hence the construct: students are asked to attempt, because students are asked to attempt essays even now). The only thing that changed/reduced in 2012 was their number. Hence, the sentence:

GMAT reduced the number of essays that students are asked to attempt as part of the GMAT exam.

Let me know if it is now making some sense:).

Hello Louis/ louisbharnabas,

I am not sure if you still have this doubt. Here is the explanation nonetheless.

Usage of past perfect tense verb denotes an action that is done and over in the distant past. This verb denotes an event that is complete and over.

Going by this logic, the original sentence says that in the past, municipalities had been allowed to dump X amount of phosphates. This means that in the distant past they were allowed to do so. This action used to take place in the past and got over in the past

In 1972, when the agreement came into existence, they were no dumping the X amount of phosphates because they had been allowed to do so in the past. They were not doing so when the agreement came to existence.

So how could the agreement reduce the amount when they were not event dumping the X amount. This is the reason why Choice A is incorrect.

In choice D, use of are allowed is correct because this sentence presents general information. The municipalities are allowed to dump X amount of phosphates which was reduced by the agreement in 1972.

Please note that the sentence will be correct if we replace the simple present tense verb are allowed with simple past tense verb was allowed as this verb tense would present general information in the past.


Hope this helps.
Thanks.
Shraddha

This is not the reason that past perfect cannot be used here. We are not referring to the act of dumping itself, but to a reduction in the AMOUNT that can be dumped. So, it is illogical to say that a 1972 agreement can reduce the amount that was dumped before the agreement was made. The agreement can only reduce the amount that is dumped in the future. So, it makes no sense to use the past perfect tense here.



Again, the way to eliminate past perfect tense here is not to say that the two events are unrelated, but to focus on the fact that the reduction is to be done after the agreement is made.

I hope this helps!

Regards,
Meghna

Dear Ashish,

As I explained in my post above, according to the intended meaning of the sentence, the agreement can only reduce the amount of phosphates that can be dumped AFTER the agreement is made. "Had been dumped" refers to the amount that was dumped BEFORE the agreement was made. So, logically, it doesn't make sense to say that the agreement can reduce this amount. The correct answer must use either the simple past tense or the present tense.

There is no real difference in meaning between "amount of phosphates" and "phosphate amount", but idiomatically, we use "number of" and "amount of". So, "amount of phosphates" is better.

I hope this helps with your doubts.

Regards,
Meghna

When you say "the action stopped," are you talking about my discussion of the past perfect in A?

To use the past perfect, we need more than an action that has stopped, or we'd end up using past perfect for all events that have ended. We don't say "I had been born in California" or "Nehru had been the first Prime Minister of India." To use past perfect, we need a sentence that mentions some past event, and we need to be describing something that preceded that past event: "Before the ruling was made, I had been crossing the border every day." "I had studied French for three years when I finally visited France."

As for the present tense in D, maybe it will help to think of it this way. There is an amount that municipalities are allowed to dump. The 1972 agreement reduced that amount, and we are still at that reduced amount. So the amount that municipalities are currently allowed to dump is lower than it used to be. Why? Because the 1972 agreement reduced it.

We could have used "were" instead of "are," but that would restrict the scope to the past, leaving it unclear whether the reduction is still in place, or whether such a limitation even exists anymore! It also would have made this question a lot less tough. However, using the past perfect would be the worst of all. As I said before, since past perfect describes events that precede another past event, this would place the allowance first in our order, meaning that the change affected how much people had already been allowed to dump. In other words, we'd be saying it changed the past!

I certainly wouldn't call it an absolute rule, but I think it's completely OK to discuss a scientific theory in the present tense, since the description is a general characteristic of that theory:

The theory of spontaneous generation states that living organisms develop from nonliving matter.

Seems totally fine, right? We're describing the general characteristics of the theory of spontaneous generation, so present tense is OK. But I'm not sure that it would be WRONG, exactly, to discuss an old theory in the past tense:

The theory of spontaneous generation stated that living organisms develop from nonliving matter.

I think this is probably fine, too. Why? Well, the theory of spontaneous generation was debunked a long time ago, and you could easily argue that it's more appropriate to discuss that theory in the past tense.

Bottom line: in some situations, the difference between present tense and past tense is mostly just a stylistic choice by the author. In most cases, you'll be able to figure out which tense is correct based on the context of the sentence. But if two different tenses seem defensible, just look for other errors, and don't automatically assume that one of the two (potentially correct) tenses must be wrong.

I hope this helps, and welcome to GMAT Club, MisterD!

I think you asked about a similar question yesterday. Changing the verb tense at the end changes the meaning of the sentence. Compare these two simpler sentences (which are not perfectly written, but illustrate the point) :

"A 1995 law imposed additional fines on companies that had been polluting"

"A 1995 law imposed additional fines on companies that are polluting"

These have different meanings. The first, using "had been", says that companies that polluted before 1995 were subject to additional penalties. So that sentence describes a retroactive penalty applied to companies for the pollution they caused before the law was passed (even if those companies no longer pollute). The second sentence means something different. It says that new fines were added (to whatever fines existed before) to punish companies that pollute from 1995 onwards.

The second sentence isn't well-written, but I wanted to match the verb tenses in the original as closely as possible.

Hello again, sislam04. Your understanding is correct, but you seem to be getting caught up in hypotheticals more than the question at hand. I would have no problem with your proposed sentence above, no different from saying that the 1972 case Roe v. Wade affords women the legal right to seek out an abortion for an unwanted pregnancy... but of course, such a sentence as yours does not appear in the answer choices. (What did you select? Do you understand why it was incorrect?) As for the Constitution examples, you would have to consider the entire sentence before you could make a determination as to the correct verb tense. For instance, I could conclude the first sentence with a statement that would extend into the present:

The 1787 Constitution guaranteed representation, an idea that continues to this day.

Consider the whole sentence. Look for contextual clues that logically point to one interpretation or another. And do not be too quick to pass judgment. There might be more than meets the eye at first glance, just as choice (A) in the original question presents a clever trap.

I hope that helps. Thank you for thinking to ask me about this one.

- Andrew

Hi tinyturtle,

Yes, we do use "amount" for uncountable noun. And this rule is in play the first sentence.

1. This amount of mashed potatoes should be enough for dinner.

Mashed potatoes can not be counted because they are crushed and mashed after being boiled. Hence, it is not possible to count them.

2. This number of baked potatoes should be enough for dinner.

However, when a potato is baked, it still remains in its shape and can be counted. Hence, this sentence is correct.

Hope this helps.
Thanks.
Shraddha