Last visit was: 13 Jul 2025, 22:55 It is currently 13 Jul 2025, 22:55
Close
GMAT Club Daily Prep
Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History
Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.
Close
Request Expert Reply
Confirm Cancel
Sub 505 Level|   Idioms/Diction/Redundancy|   Parallelism|                                 
User avatar
EMPOWERgmatVerbal
User avatar
EMPOWERgmat Instructor
Joined: 23 Feb 2015
Last visit: 17 Feb 2025
Posts: 1,694
Own Kudos:
15,051
 [7]
Given Kudos: 766
Expert
Expert reply
Posts: 1,694
Kudos: 15,051
 [7]
4
Kudos
Add Kudos
3
Bookmarks
Bookmark this Post
User avatar
DmitryFarber
User avatar
Manhattan Prep Instructor
Joined: 22 Mar 2011
Last visit: 13 Jul 2025
Posts: 2,950
Own Kudos:
Given Kudos: 57
GMAT 2: 780  Q50  V50
Expert
Expert reply
GMAT Focus 1: 745 Q86 V90 DI85
Posts: 2,950
Kudos: 8,395
Kudos
Add Kudos
Bookmarks
Bookmark this Post
The problem is that "are by" doesn't mean anything here. Notice that we already have the verb "are," so one way to read B would be "are not (caused by X) but are are by y." Another way to think about it is that "caused" isn't really a verb here--it's a past participle. It describes where stomach ulcers come from, not what they do. Making it parallel to a simple verb ("are") doesn't work.

If we don't want to put "caused" before the first parallel marker ("not"), as in C, then we need it after each marker: NOT caused by x BUT caused by y. However, in this case there's no reason to use that longer form. C solves the problem much more elegantly.
Kudos
Add Kudos
Bookmarks
Bookmark this Post
DmitryFarber
The problem is that "are by" doesn't mean anything here. Notice that we already have the verb "are," so one way to read B would be "are not (caused by X) but are are by y." Another way to think about it is that "caused" isn't really a verb here--it's a past participle. It describes where stomach ulcers come from, not what they do. Making it parallel to a simple verb ("are") doesn't work.

If we don't want to put "caused" before the first parallel marker ("not"), as in C, then we need it after each marker: NOT caused by x BUT caused by y. However, in this case there's no reason to use that longer form. C solves the problem much more elegantly.
My ultimate query is to fix B like your highlighted part. Now, it make sense to me. Many many thanks DmitryFarber!

Also, one more query:
Can I add choice F as possible correct choice?
Thanks__

Quote:
Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.

A. not caused by stress, alcohol, or rich foods, but
B. not caused by stress, alcohol, or rich foods, but are by
C. caused not by stress, alcohol, or rich foods, but by
D. caused not by stress, alcohol, and rich foods, but
E. caused not by stress, alcohol, and rich foods, but are by
Possible Choice F:
F) Recently physicians have determined that stomach ulcers are caused not by stress, alcohol, and rich foods, but by a bacterium that dwells in the mucous lining of the stomach
User avatar
DmitryFarber
User avatar
Manhattan Prep Instructor
Joined: 22 Mar 2011
Last visit: 13 Jul 2025
Posts: 2,950
Own Kudos:
Given Kudos: 57
GMAT 2: 780  Q50  V50
Expert
Expert reply
GMAT Focus 1: 745 Q86 V90 DI85
Posts: 2,950
Kudos: 8,395
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Normally, we don't use "and" with lists of negatives, because it's then unclear whether we mean to negate each of the items, or just all of them together as a group. In other words, if I say "I don't have a car and a bicycle," now you don't know whether I have just one of those things or neither of them. If I say "Ulcers are not caused by X, Y, and Z," I seem to be saying that the combination of XYZ does not cause ulcers, whereas I think the intent here is to say that none of those things cause ulcers at all.
avatar
lybeaver
Joined: 04 Jun 2018
Last visit: 03 Nov 2021
Posts: 25
Own Kudos:
Given Kudos: 37
Location: Viet Nam
Concentration: Strategy, Operations
GMAT 1: 610 Q47 V27
GMAT 2: 620 Q46 V29
GMAT 3: 680 Q47 V36
GMAT 3: 680 Q47 V36
Posts: 25
Kudos: 22
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi Experts,

Are there any differences in sentence meaning between "ulcers are not caused by X but by Y" and "ulcers are caused not by X but by Y"?

TIA!
User avatar
DmitryFarber
User avatar
Manhattan Prep Instructor
Joined: 22 Mar 2011
Last visit: 13 Jul 2025
Posts: 2,950
Own Kudos:
8,395
 [2]
Given Kudos: 57
GMAT 2: 780  Q50  V50
Expert
Expert reply
GMAT Focus 1: 745 Q86 V90 DI85
Posts: 2,950
Kudos: 8,395
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
lybeaver The first version doesn't work. If we use the form "not . . . but," it creates a parallel structure. Whatever follows "not" has to match what follows "but." As long as we make our terms parallel, we can contrast as much or as little of a phrase as we want. Consider the following three options, all of which work grammatically, at least in theory:

Ulcers are NOT caused by x BUT caused by y.
Ulcers are caused NOT by x BUT by y. (This form probably strikes the best balance for this particular statement.)
Ulcers are caused by NOT x BUT y. (This doesn't work well, but keep reading.)

Most folks would find the first overly wordy, but it's not wrong, and this kind of form is quite common if the two verbs are different. For instance, we might say "Most great poems are NOT created in a flash inspiration BUT RATHER crafted painstakingly through many hours of revision."

The last form (with just x and y as parallel terms) would probably not fly on the GMAT, simply because "by not x" sounds confusing. It almost seems like we're saying that "not x" caused something. Why do that when we can fix the problem by putting "by" after "not"? However, look at this usage: "I was visited by not one but three members of the team." This makes sense, since "not one but three" is basically just a way to emphasize that three is a large number in this context. While it wouldn't be wrong to say "I was visited not by one but by three members of the team," but it doesn't create the same emphasis.

So, long story short? Start by making sure that whenever we have closed markers (not only/but also, either/or, etc.), the words/phrases after each marker match precisely. Typically, we want the exact same part of speech, although we might have, for instance, a noun in one case and a modified noun in the other. ("I want not only a cookie but also a warm blanket.") Don't automatically cut a choice for repeating too much (e.g. "not caused by X but caused by Y") unless the repetition creates an error. Then, look to make sure that the complete structure works to convey the intended meaning.
User avatar
BijayKru
Joined: 24 Sep 2018
Last visit: 28 Jan 2025
Posts: 61
Own Kudos:
Given Kudos: 27
Location: India
Concentration: Entrepreneurship, Marketing
GMAT 1: 700 Q50 V37
GMAT 1: 700 Q50 V37
Posts: 61
Kudos: 24
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.


(A) not caused by stress, alcohol, or rich foods, but

(B) not caused by stress, alcohol, or rich foods, but are by

(C) caused not by stress, alcohol, or rich foods, but by

(D) caused not by stress, alcohol, and rich foods, but

(E) caused not by stress, alcohol, and rich foods, but are by


NOT BY "X" BUT BY "Y" IS THE CORRECT PHRASE. SO C IS THE ANSWER
avatar
swatihod123
Joined: 23 Oct 2018
Last visit: 12 Jul 2022
Posts: 25
Own Kudos:
Given Kudos: 28
Posts: 25
Kudos: 12
Kudos
Add Kudos
Bookmarks
Bookmark this Post
+1 for C

caused not by stress, alcohol, or rich foods, but by- maintains parallelism (not by....but by)
User avatar
uchihaitachi
Joined: 20 Aug 2017
Last visit: 06 Jul 2024
Posts: 92
Own Kudos:
Given Kudos: 174
Posts: 92
Kudos: 227
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATNinja egmat

(C) caused not by stress, alcohol, or rich foods, but by
(E) caused not by stress, alcohol, and rich foods, but are by

Let's add one more option to this question.
If we remove "are" from option E and the option (F) becomes
(F) caused not by stress, alcohol, and rich foods, but by

Then, we do not get the idea from the non-underlined sentence that whether it is asking for one of the causes among stress, alcohol, and rich foods or all three.

Will option (F) be right or wrong? Please advice.

Thanks
User avatar
PoojanB
Joined: 09 May 2017
Last visit: 08 Dec 2020
Posts: 81
Own Kudos:
Given Kudos: 69
Location: India
GMAT 1: 610 Q42 V33
GMAT 2: 620 Q45 V31
GPA: 4
WE:Engineering (Energy)
GMAT 2: 620 Q45 V31
Posts: 81
Kudos: 94
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Points to ponder : This is a example where u can be really mechanistic about the parallelism and that's good.
So we can see a 3-2 split between 'not caused by'...and 'caused not by..'
If we want to use 'not caused by'.. construction it should be as following : not caused by x but caused by Y to maintain the parallelism.
However if we use the second structure ,t should be as following : caused not by X but by Y
With that in mind lets check the options

(A) not caused by stress, alcohol, or rich foods, but


(B) not caused by stress, alcohol, or rich foods, but are by


(C) caused not by stress, alcohol, or rich foods, but by

(D) caused not by stress, alcohol, and rich foods, but

(E) caused not by stress, alcohol, and rich foods, but are by

C is the answer
User avatar
gh2021
Joined: 09 Aug 2017
Last visit: 21 Dec 2022
Posts: 65
Own Kudos:
Given Kudos: 157
Location: United States (NJ)
GMAT 1: 700 Q49 V35
GMAT 2: 720 Q49 V39
GMAT 3: 740 Q50 V40
GMAT 4: 750 Q49 V42
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods,but a bacterium that dwells in the mucous lining of the stomach.

Concepts tested - IDIOM, PARALLELISM

Not x but y is the correct idiom form where x and y should be parallel.

Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods,but a bacterium that dwells in the mucous lining of the stomach.

(A) not caused by stress, alcohol, or rich foods, but --- caused by AND a bacterium are not parallel
(B) not caused by stress, alcohol, or rich foods, but are by --- are not, so are appears before not and is common. Shouldn't be repeated after but. It becomes the form - are not caused by x... but are by
(C) caused not by stress, alcohol, or rich foods, but by --- correct, are caused is taken common, not by x but by y is clear, succinct and parallel
(D) caused not by stress, alcohol, and rich foods, but --- same as a - by is missing after but
(E) caused not by stress, alcohol, and rich foods, but are by --- same as b, are caused not by... but are
User avatar
CrackverbalGMAT
User avatar
Major Poster
Joined: 03 Oct 2013
Last visit: 13 Jul 2025
Posts: 4,847
Own Kudos:
Given Kudos: 225
Affiliations: CrackVerbal
Location: India
Expert
Expert reply
Posts: 4,847
Kudos: 8,638
Kudos
Add Kudos
Bookmarks
Bookmark this Post
[quote="freetheking"]Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.


(A) not caused by stress, alcohol, or rich foods, but

(B) not caused by stress, alcohol, or rich foods, but are by

(C) caused not by stress, alcohol, or rich foods, but by

(D) caused not by stress, alcohol, and rich foods, but

(E) caused not by stress, alcohol, and rich foods, but are by

This is a straightforward Parallelism-based question. Parallelism covers a number of aspects such as tenses, gerunds, comparisons and correlative conjunctions.

This question tests the concept of parallelism of correlative conjunctions. Correlative conjunctions are joining words that are used in pairs. The pairing is idiomatic or fixed in usage.

There are two aspects of parallelism of correlative conjunctions:
• The idiomatic pair must be used; the conjunctions cannot be mixed up. For example, either cannot be followed by nor. The various pairs of correlative conjunctions are either-or, neither-nor, not only-but also, from-to, between-and, both-and not-but.
E.g.: We can play both tennis as well as badminton here. (incorrect)
We can play both tennis and badminton here. (correct)

• The two conjunctions must be followed by the same part of speech. For example, if ‘either’ is followed by a verb, ‘or’ must also be followed by a verb in the sentence.
E.g.: I neither want chocolate nor ice cream. (incorrect because ‘neither’ is followed by the verb ‘want’ but ‘nor’ is followed by the noun ‘ice cream’.)

I want neither chocolate nor ice cream. (correct because both the conjunctions are followed by nouns.)

In the given question, the correlative conjunctions ‘not-but’ have been used. The sentence contains a verb in the passive form – are caused. The helping/auxiliary verb ‘are’ is in the non-underlined portion of the sentence. But the participle ‘caused’ is in the underlined portion of the sentence. The helping verb and participle should be together in order to maintain parallelism in the sentence.

Let us analyze the options according to rule 2 of parallelism of correlative conjunctions –
(A) not caused by stress, alcohol, or rich foods, but
- Incorrect because the conjunction ‘not’ is followed by the verb(participle) ‘caused’ and the conjunction ‘but’ is followed by a noun ‘a bacterium’ (in the non-underlined part of the sentence)

(B) not caused by stress, alcohol, or rich foods, but are by
- Incorrect because the conjunction ‘not’ is followed by the verb (participle) ‘caused’ and the conjunction ‘but’ is followed by the helping/auxiliary verb ‘are’. The helping verb is already present in the non-underlined part of the sentence. If a verb is to be repeated, the participle form ‘caused’ is to be repeated.

(C) caused not by stress, alcohol, or rich foods, but by
- Correct because the participle ‘caused’ has been shifted next to the helping/auxiliary verb ‘are’ and the conjunctions ‘not’ and ‘but’ are bith followed by the preposition ‘by’.

(D) caused not by stress, alcohol, and rich foods, but
- Incorrect because the conjunction ‘not’ is followed by the preposition ‘by’ and the conjunction ‘but’ is followed by the noun ‘a bacterium’(in the non-underlined part of the sentence).

(E) caused not by stress, alcohol, and rich foods, but are by
- Incorrect because the conjunction ‘not’ is followed by the preposition ‘by’ and the conjunction ‘but’ is followed by the helping verb ‘are’.

Therefore, C is the most appropriate option.
Jayanthi Kumar.
User avatar
Kinshook
User avatar
Major Poster
Joined: 03 Jun 2019
Last visit: 13 Jul 2025
Posts: 5,700
Own Kudos:
Given Kudos: 161
Location: India
GMAT 1: 690 Q50 V34
WE:Engineering (Transportation)
Products:
GMAT 1: 690 Q50 V34
Posts: 5,700
Kudos: 5,219
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Recently physicians have determined
that stomach ulcers are not caused by stress, alcohol, or rich foods,
but
a bacterium that dwells in the mucous lining of the stomach.


(A) not caused by stress, alcohol, or rich foods, but

(B) not caused by stress, alcohol, or rich foods, but are by

(C) caused not by stress, alcohol, or rich foods, but by

(D) caused not by stress, alcohol, and rich foods, but

(E) caused not by stress, alcohol, and rich foods, but are by


IMO C
Parallelism; Diction

The formula used in this sentence not this but that requires parallel elements following not and but. This means that not by stress, alcohol, or rich foods must be balanced by but by a bacterium. . . . There is no need to repeat the verb are caused, or even the auxiliary verb are, because the verb precedes the not by … but by … formula. The substitution of the conjunction and for the conjunction or changes the meaning of the sentence: Stress, alcohol and rich foods identifies the combination of these three factors as a suggested cause of stomach ulcers, whereas stress, alcohol, or rich foods offers three individual possibilities. There is no way to tell which one of these is the intended meaning of the sentence.

(A) To preserve parallelism, but should be followed by by.
(B) There is no reason to repeat the auxiliary verb are.
(C) Correct. This sentence correctly uses the not by … but by … formula.
(D) To preserve parallelism, but should be followed by by.
(E) To preserve parallelism, but should be followed by by.
[/quote]
avatar
mba757
avatar
Current Student
Joined: 15 Jun 2020
Last visit: 04 Aug 2022
Posts: 308
Own Kudos:
Given Kudos: 245
Location: United States
GPA: 3.3
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hello experts!

Is there a notable meaning difference between "not caused by" and "caused not by"? Moreover, is it always the case that you need to follow up the helping verb IMMEDIATELY with another verb? (e.g., "are CAUSED...") Or can you have "not" or another word in between?
User avatar
GMATNinja
User avatar
GMAT Club Verbal Expert
Joined: 13 Aug 2009
Last visit: 13 Jul 2025
Posts: 7,349
Own Kudos:
68,526
 [2]
Given Kudos: 1,964
Status: GMAT/GRE/LSAT tutors
Location: United States (CO)
GMAT 1: 780 Q51 V46
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
GRE 2: Q170 V170
Products:
Expert
Expert reply
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
GRE 2: Q170 V170
Posts: 7,349
Kudos: 68,526
 [2]
2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
samgyupsal
Hello experts!

Is there a notable meaning difference between "not caused by" and "caused not by"? Moreover, is it always the case that you need to follow up the helping verb IMMEDIATELY with another verb? (e.g., "are CAUSED...") Or can you have "not" or another word in between?
The two phrases create different expectations for what's likely to follow. If I see "not caused by," all I know is that afterwards I'm getting the noun that is not responsible for something. For example:

    After much deliberation, Tim's doctor determined that the rash was not caused by the 17 bags of Skittles Tim consumed.

Here, we get one element that is not responsible for Tim's rash: the 17 bags of Skittles. Simple enough.

However, "caused not by" signals to the reader that we're going to get two pieces next: the element that is not responsible, as well as whatever is responsible:

    After much deliberation, Tim's doctor determined that the rash was caused not by the 17 bags of Skittles Tim consumed but by the toilet bowl cleaner he'd rubbed all over his face and chest.

So now we have two pieces of information: what didn't cause Tim's rash, as well as the real culprit.

As for "immediately," there's no rule. It's an adverb, so it's telling us when an action occurs, but it doesn't have to come right before the verb it modifies. I could write, "Tim immediately experienced itchiness and watery eyes," but I could also write "Immediately, Tim experienced itchiness and watery eyes." Either is fine.

I hope that helps!
avatar
ChiragPrajapati
Joined: 29 Jun 2020
Last visit: 13 Oct 2024
Posts: 1
Given Kudos: 25
Posts: 1
Kudos: 0
Kudos
Add Kudos
Bookmarks
Bookmark this Post
freetheking
Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.

If we move the verb 'caused' inside the Trigger 'not-but' we will need another verb parallel to that, but as we already have the word 'are' outside, it makes no sense. Hence, A and B are out.

(A) not caused by stress, alcohol, or rich foods, but

(B) not caused by stress, alcohol, or rich foods, but are by

Comparing C, D and E, we have a preposition after the trigger 'not' so we will also need a preposition after 'but' hence C
(C) caused not by stress, alcohol, or rich foods, but by
(D) caused not by stress, alcohol, and rich foods, but
(E) caused not by stress, alcohol, and rich foods, but are by

Parallelism; Diction

The formula used in this sentence not this but that requires parallel elements following not and but. This means that not by stress, alcohol, or rich foods must be balanced by but by a bacterium. . . . There is no need to repeat the verb are caused, or even the auxiliary verb are, because the verb precedes the not by … but by … formula. The substitution of the conjunction and for the conjunction or changes the meaning of the sentence: Stress, alcohol and rich foods identifies the combination of these three factors as a suggested cause of stomach ulcers, whereas stress, alcohol, or rich foods offers three individual possibilities. There is no way to tell which one of these is the intended meaning of the sentence.

(A) To preserve parallelism, but should be followed by by.
(B) There is no reason to repeat the auxiliary verb are.
(C) Correct. This sentence correctly uses the not by … but by … formula.
(D) To preserve parallelism, but should be followed by by.
(E) To preserve parallelism, but should be followed by by.
avatar
PRNDL
Joined: 03 Nov 2019
Last visit: 24 Jul 2022
Posts: 26
Own Kudos:
Given Kudos: 87
Posts: 26
Kudos: 2
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Is it okay to write

" not caused by stress, alcohol, or rich foods, but by "

I think that the missing "caused" after "but" should be an error
User avatar
100mitra
Joined: 29 Apr 2019
Last visit: 06 Jul 2022
Posts: 716
Own Kudos:
Given Kudos: 49
Status:Learning
Posts: 716
Kudos: 617
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Correct Answer : C

Correct idiom : Casued not by X, But by Y
Parallelsim : We need check after parallelism indicators like (,and)(,or) etc the structure must be same

Recently physicians have determined that stomach ulcers are not caused by stress, alcohol, or rich foods, but a bacterium that dwells in the mucous lining of the stomach.
(A) not caused by stress, alcohol, or rich foods, but
(B) not caused by stress, alcohol, or rich foods, but are by
(C) caused not by stress, alcohol, or rich foods, but by
(D) caused not by stress, alcohol, and rich foods, but
(E) caused not by stress, alcohol, and rich foods, but are by
   1   2   3   
Moderators:
GMAT Club Verbal Expert
7349 posts
GMAT Club Verbal Expert
235 posts