BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

Polio - OG explanation confusion

This topic has expert replies
Post new topic Locked
Previous Topic Next Topic
User avatar
Legendary Member
Posts: 1172
Joined: Wed Apr 28, 2010 6:20 pm
Thanked: 74 times
Followed by:4 members

Polio - OG explanation confusion

by uwhusky » Sun Aug 01, 2010 9:38 am
Polio, although it is eradicated in the United States, it continues elsewhere and is able to be brought into the country by visitors.

(A) Polio, although it is eradicated in the United States, it continues elsewhere and is able to be
(B) Polio, although eradicated in the United States, it still continues elsewhere and can be
(C) Although still continuing elsewhere, polio has been eradicated in the United States and could be
(D) Although having been eradicated in the United States, polio still continues elsewhere and is capable of being
(E) Although eradicated in the United States, polio continues elsewhere and could be

[spoiler]This is question 36 in the Verbal Review Guide 2nd edition. My confusion is in the answer key, "...about a single subject, polio (that it continues elsewhere, and that it can be brought back into the United States)."

Why would the answer explanation use present tense "can", but then the answer itself uses past tense "could"? Is it because the context of the answer is "although eradicated in the US, polio...and could be?" I am very confused, please clarify. [/spoiler]
Yep.
Top
Source: — Sentence Correction |
User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pm
Thanked: 215 times
Followed by:7 members

by kvcpk » Sun Aug 01, 2010 9:43 am
Is the OA E?
Top
User avatar
Legendary Member
Posts: 1172
Joined: Wed Apr 28, 2010 6:20 pm
Thanked: 74 times
Followed by:4 members

by uwhusky » Sun Aug 01, 2010 9:49 am
Yes. But the explanation to the question in OG seems to contradict the answer on tense for "can".

I was initially questioning why "polio continues elsewhere and could be..." have different tense, but then seeing the answer explanation really made me wonder why.
Yep.
Top
User avatar
Legendary Member
Posts: 1893
Joined: Sun May 30, 2010 11:48 pm
Thanked: 215 times
Followed by:7 members

by kvcpk » Sun Aug 01, 2010 9:52 am
uwhusky wrote:Yes. But the explanation to the question in OG seems to contradict the answer on tense for "can".
I do not know about the explanation in OG uwhusky, I am sorry. I see that the modifier is rightly set only in E. I am sure that you would have found this too. So not much of a help from my side.
Top
User avatar
Legendary Member
Posts: 1172
Joined: Wed Apr 28, 2010 6:20 pm
Thanked: 74 times
Followed by:4 members

by uwhusky » Sun Aug 01, 2010 9:59 am
I pmed one of the experts, maybe he can shed some light to this question

The basis for my question is that in general SC readings, all the explanation says not to change tense in parallel construction:

"John runs to school in the morning and runs back home in the afternoon."

But in this answer "polio continues elsewhere and could be...", continues and could have different tense. So I thought it might be because of "eradicated..." in the earlier part. However, I noticed the explanation used consistent tense "polio continues elsewhere and can be...", and that made me really confused.
Last edited by uwhusky on Sun Aug 01, 2010 10:00 am, edited 1 time in total.
Yep.
Top
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 am
Thanked: 135 times
Followed by:7 members

by selango » Sun Aug 01, 2010 10:00 am
uwhusky,

There is no verb tense problem in option B.This option is incorrect because of the use of pronoun "it".
--Anand--
Top
User avatar
Legendary Member
Posts: 1172
Joined: Wed Apr 28, 2010 6:20 pm
Thanked: 74 times
Followed by:4 members

by uwhusky » Sun Aug 01, 2010 10:01 am
selango wrote:uwhusky,

There is no verb tense problem in option B.This option is incorrect because of the use of pronoun "it".
That's not the basis of my question though. Further explanation in the subsequent post.
Yep.
Top
User avatar
Legendary Member
Posts: 1460
Joined: Tue Dec 29, 2009 1:28 am
Thanked: 135 times
Followed by:7 members

by selango » Sun Aug 01, 2010 10:12 am
The usual sequence is "Present+Future" or "Past+Conditional"

"Could be" is conditional.

Because of "eradicated" in past tense,the conditional "could be" is used.

However it also use the present tense "Continues".So "Present+Conditional" is used and tense mismatch.

Am I right?
--Anand--
Top
User avatar
Legendary Member
Posts: 1172
Joined: Wed Apr 28, 2010 6:20 pm
Thanked: 74 times
Followed by:4 members

by uwhusky » Sun Aug 01, 2010 10:14 am
Yes, that's pretty much the basis of my confusion.
Yep.
Top
Master | Next Rank: 500 Posts
Posts: 364
Joined: Tue Apr 20, 2010 5:13 am
Thanked: 31 times
Followed by:3 members

by FightWithGMAT » Sun Aug 01, 2010 10:50 am
uwhusky wrote:Polio, although it is eradicated in the United States, it continues elsewhere and is able to be brought into the country by visitors.

(A) Polio, although it is eradicated in the United States, it continues elsewhere and is able to be
(B) Polio, although eradicated in the United States, it still continues elsewhere and can be
(C) Although still continuing elsewhere, polio has been eradicated in the United States and could be
(D) Although having been eradicated in the United States, polio still continues elsewhere and is capable of being
(E) Although eradicated in the United States, polio continues elsewhere and could be

[spoiler]This is question 36 in the Verbal Review Guide 2nd edition. My confusion is in the answer key, "...about a single subject, polio (that it continues elsewhere, and that it can be brought back into the United States)."

Why would the answer explanation use present tense "can", but then the answer itself uses past tense "could"? Is it because the context of the answer is "although eradicated in the US, polio...and could be?" I am very confused, please clarify. [/spoiler]
I do not see any tense issue here in E.

COULD is used to show possibility.

It could rain today.
The announcement could happen any time.

Both the above sentences are in present tense.

Replace Could with CAN....the sentence sounds weird.
Top
User avatar
Legendary Member
Posts: 1083
Joined: Wed Feb 24, 2010 9:38 pm
Thanked: 127 times
Followed by:14 members

by gmat_perfect » Sun Aug 01, 2010 12:21 pm
uwhusky wrote:Polio, although it is eradicated in the United States, it continues elsewhere and is able to be brought into the country by visitors.

(A) Polio, although it is eradicated in the United States, it continues elsewhere and is able to be
(B) Polio, although eradicated in the United States, it still continues elsewhere and can be
(C) Although still continuing elsewhere, polio has been eradicated in the United States and could be
(D) Although having been eradicated in the United States, polio still continues elsewhere and is capable of being
(E) Although eradicated in the United States, polio continues elsewhere and could be

[spoiler]This is question 36 in the Verbal Review Guide 2nd edition. My confusion is in the answer key, "...about a single subject, polio (that it continues elsewhere, and that it can be brought back into the United States)."

Why would the answer explanation use present tense "can", but then the answer itself uses past tense "could"? Is it because the context of the answer is "although eradicated in the US, polio...and could be?" I am very confused, please clarify. [/spoiler]

COULD is used to show possibility:

"Could" is used to express possibility or past ability as well as to make suggestions and requests. "Could" is also commonly used in conditional sentences as the conditional form of "can."

Examples:

Extreme rain could cause the river to flood the city. possibility
Nancy could ski like a pro by the age of 11. past ability
You could see a movie or go out to dinner. suggestion
Could I use your computer to email my boss? request
We could go on the trip if I didn't have to work this weekend. conditional.

Reference: https://www.englishpage.com/modals/could.html

A story:

My hand bag has been lost. I don't know who has stolen it. I have doubt on the behavior of John.

=> He could take the bag. [Just possibility]
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Sun Aug 01, 2010 12:59 pm
uwhusky wrote:Polio, although it is eradicated in the United States, it continues elsewhere and is able to be brought into the country by visitors.

(A) Polio, although it is eradicated in the United States, it continues elsewhere and is able to be
(B) Polio, although eradicated in the United States, it still continues elsewhere and can be
(C) Although still continuing elsewhere, polio has been eradicated in the United States and could be
(D) Although having been eradicated in the United States, polio still continues elsewhere and is capable of being
(E) Although eradicated in the United States, polio continues elsewhere and could be

[spoiler]This is question 36 in the Verbal Review Guide 2nd edition. My confusion is in the answer key, "...about a single subject, polio (that it continues elsewhere, and that it can be brought back into the United States)."

Why would the answer explanation use present tense "can", but then the answer itself uses past tense "could"? Is it because the context of the answer is "although eradicated in the US, polio...and could be?" I am very confused, please clarify. [/spoiler]
In A and B, the pronoun it is unnecessary. Eliminate A and B.

In C and D, the adverb still creates an error of redundancy because the verbs continuing (in C) and continues (in D) on their own express ongoing action. Eliminate C and D.

The correct answer is E.

There is a difference in meaning between can and could: whereas can expresses ability, could expresses possibility. In this SC, could is better because the intended meaning of the sentence is that there is the possibility of the importing polio into the US.

Hope this helps!
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
User avatar
Legendary Member
Posts: 1172
Joined: Wed Apr 28, 2010 6:20 pm
Thanked: 74 times
Followed by:4 members

by uwhusky » Sun Aug 01, 2010 1:14 pm
https://www.merriam-webster.com/dictionary/could
Main Entry: could
Pronunciation: \kəd, ˈku̇d\
Function: verbal auxiliary
Etymology: Middle English couthe, coude, from Old English cūthe; akin to Old High German konda could
Date: 13th century
past of can

-used in auxiliary function in the past <we found we could go>, in the past conditional <we said we would go if we could>, and as an alternative to can suggesting less force or certainty or as a polite form in the present <if you could come we would be pleased>
"past of can" is the basis of my confusion. I thought I knew the difference between could and can until I was told that "could" is past tense of "can".

You can find examples of "would" and "will", whereas "would" is used for conditional of a past event and "will" is for conditional of current event.

The issue I have is focus on figuring out the difference between the two, when is it for tense, and when is it for conditional clause, because I am not getting a clear idea of the usage when it comes to tense.

Going back to the explanation in OG to this question again, if there's difference between "can" and "could" in meaning, why does the explanation used "can", but the answer uses "could"?
Yep.
Top
User avatar
GMAT Instructor
Posts: 15539
Joined: Tue May 25, 2010 12:04 pm
Location: New York, NY
Thanked: 13060 times
Followed by:1906 members
GMAT Score:790

by GMATGuruNY » Sun Aug 01, 2010 2:02 pm
uwhusky wrote:https://www.merriam-webster.com/dictionary/could
Main Entry: could
Pronunciation: \kəd, ˈku̇d\
Function: verbal auxiliary
Etymology: Middle English couthe, coude, from Old English cūthe; akin to Old High German konda could
Date: 13th century
past of can

-used in auxiliary function in the past <we found we could go>, in the past conditional <we said we would go if we could>, and as an alternative to can suggesting less force or certainty or as a polite form in the present <if you could come we would be pleased>
"past of can" is the basis of my confusion. I thought I knew the difference between could and can until I was told that "could" is past tense of "can".

You can find examples of "would" and "will", whereas "would" is used for conditional of a past event and "will" is for conditional of current event.

The issue I have is focus on figuring out the difference between the two, when is it for tense, and when is it for conditional clause, because I am not getting a clear idea of the usage when it comes to tense.

Going back to the explanation in OG to this question again, if there's difference between "can" and "could" in meaning, why does the explanation used "can", but the answer uses "could"?
To help with the explanation in the OG, I'd need to see the entire explanation.

I can tell you this: could has more than one use. In the sentence below, could is the past tense of can:

Yesterday John could run fast, but today he can't. (Yesterday John was able to run fast, but today he is unable to run fast.)

Another use is to express possibility:

If John had the energy, he could run fast. (It is possible for John to run fast, but he does not have the energy.)

We need to examine the rest of the sentence in order to determine how could is being used.
Private tutor exclusively for the GMAT and GRE, with over 20 years of experience.
Followed here and elsewhere by over 1900 test-takers.
I have worked with students based in the US, Australia, Taiwan, China, Tajikistan, Kuwait, Saudi Arabia -- a long list of countries.
My students have been admitted to HBS, CBS, Tuck, Yale, Stern, Fuqua -- a long list of top programs.

As a tutor, I don't simply teach you how I would approach problems.
I unlock the best way for YOU to solve problems.

For more information, please email me (Mitch Hunt) at [email protected].
Student Review #1
Student Review #2
Student Review #3
Top
User avatar
Legendary Member
Posts: 1172
Joined: Wed Apr 28, 2010 6:20 pm
Thanked: 74 times
Followed by:4 members

by uwhusky » Sun Aug 01, 2010 3:26 pm
This is what the answer explanation said:

"This sentence makes two main claims about a single subject, polio (that it continues elsewhere, and that it can be brought back into the United States). The claim that polio has been eradicated in the United States is a condition of the other two claims and is best expressed in a subordinate clause."

Then it goes into explanation of each answer.

So my confusion is if "could" and "can" is used as different meaning as oppose to different tense, why is it the explanation use "can" when the context remains the same and the answer says "could".

But thank you very much for the added example of the difference in tense, I think I sort of understand the concept a bit better now. So "could" and "can" are different in terms of meaning, but "could" can be used as past tense for "can" under certain context, and same with vice versa?
Yep.
Top
Post new topic Locked