Last visit was: 19 Nov 2025, 06:04 It is currently 19 Nov 2025, 06:04
Home
GMAT
Messages
Tests
Schools
Events
Rewards
Chat
My Profile
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.
Go to My Error Log Learn more
Close
Request Expert Reply
Confirm Cancel
Back to Forum
Create Topic
   1   2   3 
555-605 Level|   Meaning/Logical Predication|   Modifiers|   Pronouns|   Verb Tense/Form|                           
User avatar
daagh
User avatar
Major Poster
Joined: 19 Feb 2007
Last visit: 16 Oct 2020
Posts: 5,264
Own Kudos:
42,418
Given Kudos: 422
Status: enjoying
Location: India
WE:Education (Education)
Expert
Expert reply
Posts: 5,264
Kudos: 42,418
Although the first pulsar, or rapidly spinning collapsed star, to be 12 Jun 2020, 23:48
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Leena
Unless you reproduce the actual choice and the various sequences, I can't be searching for what you are meaning.
User avatar
shanks2020
User avatar
Joined: 02 Dec 2018
Last visit: 21 Mar 2024
Posts: 239
Own Kudos:
39
Given Kudos: 70
Posts: 239
Kudos: 39
Although the first pulsar, or rapidly spinning collapsed star, to be 13 Jun 2020, 12:08
Kudos
Add Kudos
Bookmarks
Bookmark this Post
GMATNinja
zoezhuyan
GMATNinja


The use of the past perfect tense (“had not been announced”) also isn’t great in (A). That verb tense needs to describe an action that happens BEFORE some other action in the past. But in this case, it’s backwards: the pulsar was observed in 1967, but then it was announced later, in 1968 – so it’s awfully strange to use the past perfect tense to discuss the 1968 announcement, given the context of the sentence.


Dear @GMATNinja,mikemcgarry, GMATNinjaTwo, GMATNinja, MagooshExpert Carolyn,
sayantanc2
VeritasPrepKarishma

I genuinely need you experts' help

verb tens is so hard for foreigners.

As GMATNinja explains above, I think I can understand what your point.
but, I am still confused.

I read a correct example from Manhattan guide,
Quote:

The band U2 WAS just one of many new groups on the rock music scene in the early 1980s, but less than ten years later, U2 HAD fully ECLIPSED its early rival in the pantheon of popular music.

my interpretation of HAD fully ECLIPSED is the timeframeless than ten years later,
more important point of this sentence is that a past perfect HAD fully ECLIPSED is not earlier action in the sentence,

similarly, in this case, I think HAD not BEEN ANNOUNCED is not a earlier action although HAD fully ECLIPSED is correct because the timeframe "UNTIL FEBRUARY 1968",
So I think the meaning is sound.
First, you want to be very, very careful about interpreting a non-official sentence as an authoritative representation of how the GMAT handles a certain concept. If you want to analyze official GMAT sentences in an effort to figure out how, exactly, the GMAT handles the past perfect tense, that would be fine. But I think it's a mistake to assume that questions written by a test-prep company (my own included!) -- perfectly mimic the GMAT's handling of any particular grammar issue.

In other words: official GMAT sentences are a good authority on the GMAT's usage of past perfect tense; non-official sentences are not.

So I won't analyze the U2 example, but let's get back to the original sentence:

Quote:
Although the first pulsar... to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.
I think that part of the confusion is that the action in past perfect ("had not been announced") isn't really an action at all -- it's the absence of any action, since the discovery "had NOT been announced". But still, the sentence is very clearly trying to draw a distinction between two time periods: in 1967 (the earlier period), the discovery was made, and in 1968 (the later period) the discovery was announced. And it's just nonsensical to use past perfect to describe what happened -- or didn't happen -- in the LATER period (1968).

And even if you don't believe a word of that, there are still plenty of other reasons to eliminate (A). :)

I hope this helps!
Show more

Hi GMATNinja

Just from tenses point of view, would it be correct then to use past past perfect for the sighting(first pulsar to be sighted had been in 1967, ...was not announced until Feb 1968?

Also does this sentence mean that it was announced in Feb 1968?
From my interpretation, it means that the announcement could be anytime after Feb 1968.
Hence, i belive past perfect should not be an issue if we consider observing and announcing as independent events?
Your thoughts?
User avatar
KarishmaB
User avatar
Joined: 16 Oct 2010
Last visit: 18 Nov 2025
Posts: 16,267
Own Kudos:
76,992
 [4]
Given Kudos: 482
Location: Pune, India
Expert
Expert reply
Active GMAT Club Expert! Tag them with @ followed by their username for a faster response.
Posts: 16,267
Kudos: 76,992
 [4]
Although the first pulsar, or rapidly spinning collapsed star, to be 16 Jun 2020, 02:49
2
Kudos
Add Kudos
2
Bookmarks
Bookmark this Post
LeenaSai
GMATNinja
zoezhuyan
GMATNinja


The use of the past perfect tense (“had not been announced”) also isn’t great in (A). That verb tense needs to describe an action that happens BEFORE some other action in the past. But in this case, it’s backwards: the pulsar was observed in 1967, but then it was announced later, in 1968 – so it’s awfully strange to use the past perfect tense to discuss the 1968 announcement, given the context of the sentence.


Dear @GMATNinja,mikemcgarry, GMATNinjaTwo, GMATNinja, MagooshExpert Carolyn,
sayantanc2
VeritasPrepKarishma

I genuinely need you experts' help

verb tens is so hard for foreigners.

As GMATNinja explains above, I think I can understand what your point.
but, I am still confused.

I read a correct example from Manhattan guide,
Quote:

The band U2 WAS just one of many new groups on the rock music scene in the early 1980s, but less than ten years later, U2 HAD fully ECLIPSED its early rival in the pantheon of popular music.

my interpretation of HAD fully ECLIPSED is the timeframeless than ten years later,
more important point of this sentence is that a past perfect HAD fully ECLIPSED is not earlier action in the sentence,

similarly, in this case, I think HAD not BEEN ANNOUNCED is not a earlier action although HAD fully ECLIPSED is correct because the timeframe "UNTIL FEBRUARY 1968",
So I think the meaning is sound.
First, you want to be very, very careful about interpreting a non-official sentence as an authoritative representation of how the GMAT handles a certain concept. If you want to analyze official GMAT sentences in an effort to figure out how, exactly, the GMAT handles the past perfect tense, that would be fine. But I think it's a mistake to assume that questions written by a test-prep company (my own included!) -- perfectly mimic the GMAT's handling of any particular grammar issue.

In other words: official GMAT sentences are a good authority on the GMAT's usage of past perfect tense; non-official sentences are not.

So I won't analyze the U2 example, but let's get back to the original sentence:

Quote:
Although the first pulsar... to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.
I think that part of the confusion is that the action in past perfect ("had not been announced") isn't really an action at all -- it's the absence of any action, since the discovery "had NOT been announced". But still, the sentence is very clearly trying to draw a distinction between two time periods: in 1967 (the earlier period), the discovery was made, and in 1968 (the later period) the discovery was announced. And it's just nonsensical to use past perfect to describe what happened -- or didn't happen -- in the LATER period (1968).

And even if you don't believe a word of that, there are still plenty of other reasons to eliminate (A). :)

I hope this helps!

Hi there, VeritasKarishma egmat

I couldn’t understand the sequencing of events in option D :

I am able to eliminate the rest of the provided options on the basis of following reasons :

1) Sequencing of events - ( option A and Option C)

2) Sighted Pulsar( Pulsar is non living so , using “Sighted” would be irrelevant ) — ( Option E)

3) Modifier issue ( Option B)

By this way, I am able to eliminate options A,B,C,E

But the major challenge is : while analysing option D , I couldn’t stop myself from striking it off on the basis of Sequencing of events !


Kindly help

Posted from my mobile device
Show more


There is no doubt about the sequencing of events in this sentence. The sentence clearly mentions the time line:
Observed in summer of 1967 and not announced from then till Feb 1968.
So use of simple past for both works perfectly.
User avatar
dracarys007
User avatar
Joined: 04 Jun 2020
Last visit: 24 Feb 2022
Posts: 68
Own Kudos:
223
Given Kudos: 16
Location: India
Concentration: Strategy, General Management
Schools: Harvard '23 INSEAD Aug 22 intake Sloan '23
GPA: 3.4
WE:Engineering (Consulting)
Schools: Harvard '23 INSEAD Aug 22 intake Sloan '23
Posts: 68
Kudos: 223
Although the first pulsar, or rapidly spinning collapsed star, to be 26 Jul 2020, 09:35
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Appreciation keep me motivated. Don’t Shy away.
Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, - This is a subordinate clause with although. This shows contrast.
it had not been announced until February, 1968.
It is unlear what the it refers to 1) star or 2) the event.

Had is used to show two actions in the past and had appears with the earlier event. Hence this is incorrect.



(A) Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.

This choice is incorrect for the afore mentioned reasons.

(B) Although not announced until February, 1968, in the summer of 1967 graduate student Jocelyn Bell observed the first pulsar, or rapidly spinning collapsed star, to be sighted.
It appears that the summer was not announced until 1968.

(C) Although observed by graduate student Jocelyn Bell in the summer of 1967, the discovery of the first sighted pulsar, or rapidly spinning collapsed star, had not been announced before February, 1968.
This choice changes the meaning of the sentence to say that the discovery was observed.

(D) The first pulsar, or rapidly spinning collapsed star, to be sighted was observed in the summer of 1967 by graduate student Jocelyn Bell, but the discovery was not announced until February, 1968.
This appears to be the correct choice. No obvious errors. Let keep this one and move on.

(E) The first sighted pulsar, or rapidly spinning collapsed star, was not announced until February, 1968, while it was observed in the summer of 1967 by graduate student Jocelyn Bell.
This changes the meaning of the sentence. The action of announcing was not done when observing was in progress.
The winner is D.
User avatar
jkrishh7
User avatar
Joined: 06 Feb 2020
Last visit: 16 Sep 2020
Posts: 37
Own Kudos:
21
Given Kudos: 18
Status:When going gets tough, tough gets going_GMAT2020
Location: India
Concentration: Finance, Entrepreneurship
WE:Engineering (Military & Defense)
Posts: 37
Kudos: 21
Although the first pulsar, or rapidly spinning collapsed star, to be 08 Aug 2020, 08:22
Kudos
Add Kudos
Bookmarks
Bookmark this Post
[quote="bakfed"]Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.


(A) Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.

(B) Although not announced until February, 1968, in the summer of 1967 graduate student Jocelyn Bell observed the first pulsar, or rapidly spinning collapsed star, to be sighted.

(C) Although observed by graduate student Jocelyn Bell in the summer of 1967, the discovery of the first sighted pulsar, or rapidly spinning collapsed star, had not been announced before February, 1968.

(D) The first pulsar, or rapidly spinning collapsed star, to be sighted was observed in the summer of 1967 by graduate student Jocelyn Bell, but the discovery was not announced until February, 1968.

(E) The first sighted pulsar, or rapidly spinning collapsed star, was not announced until February, 1968, while it was observed in the summer of 1967 by graduate student Jocelyn Bell.

**********************************************
(A) the event happened earlier uses 'had'
(B) What was not announced until Feb 1968? The answer should come after the comma
(C) What was observed by the student? Is it discovery?
(D) Resolves all issues-Correct
(E) While changes the meaning as if both happening concurrently. No logic
avatar
Kanupurumishra
avatar
Joined: 05 Apr 2020
Last visit: 08 Aug 2022
Posts: 1
Given Kudos: 53
Posts: 1
Kudos: 0
Although the first pulsar, or rapidly spinning collapsed star, to be 01 Sep 2020, 10:20
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Hi,
Can someone explain the error of using "Comma + While" in option E.
Thanks
User avatar
MartyTargetTestPrep
User avatar
Target Test Prep Representative
Joined: 24 Nov 2014
Last visit: 11 Aug 2023
Posts: 3,476
Own Kudos:
5,579
 [2]
Given Kudos: 1,430
Status:Chief Curriculum and Content Architect
Affiliations: Target Test Prep
GMAT 1: 800 Q51 V51
Expert
Expert reply
GMAT 1: 800 Q51 V51
Posts: 3,476
Kudos: 5,579
 [2]
Although the first pulsar, or rapidly spinning collapsed star, to be 02 Sep 2020, 07:48
1
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Kanupurumishra
Hi,
Can someone explain the error of using "Comma + While" in option E.
Thanks
Show more
"While" can be used in two different ways.

"While" can mean "whereas" and indicate that a contrast is being expressed, or it can mean "at the time when."

In this case, neither meaning of "while" makes sense.

It does not make sense to contrast the announcing of the star in 1968 with the observation of the star in 1967.

It does not make sense to say that the first sighted pulsar was announced in February, 1968, at the time when it was observed in the summer of 1967.

So, we can see that the use of "while" in that context does not make sense.
avatar
TarunKumar1234
avatar
Joined: 14 Jul 2020
Last visit: 28 Feb 2024
Posts: 1,107
Own Kudos:
1,348
 [1]
Given Kudos: 351
Location: India
Posts: 1,107
Kudos: 1,348
 [1]
Although the first pulsar, or rapidly spinning collapsed star, to be 20 Dec 2020, 00:18
Kudos
Add Kudos
1
Bookmarks
Bookmark this Post
Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.


(A) Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.-> why do we need "had not been" for recent event.

(B) Although not announced until February, 1968, in the summer of 1967 graduate student Jocelyn Bell observed the first pulsar, or rapidly spinning collapsed star, to be sighted.-> Incorrect modifier for "not announced until February"

(C) Although observed by graduate student Jocelyn Bell in the summer of 1967, the discovery of the first sighted pulsar, or rapidly spinning collapsed star, had not been announced before February, 1968.-> why do we need "had not been" for recent event.

(D) The first pulsar, or rapidly spinning collapsed star, to be sighted was observed in the summer of 1967 by graduate student Jocelyn Bell, but the discovery was not announced until February, 1968. -> awkward! But, The first pulsar to be sighted was observed in the summer of 1967...makes sense. Let's keep it.

(E) The first sighted pulsar, or rapidly spinning collapsed star, was not announced until February, 1968, while it was observed in the summer of 1967 by graduate student Jocelyn Bell.-> "The first sighted pulsar was not announced until February" No!, the sighting was not announced. Meaning changed.

So, I think D. :)
User avatar
CEdward
User avatar
Joined: 11 Aug 2020
Last visit: 14 Apr 2022
Posts: 1,203
Own Kudos:
272
Given Kudos: 332
Posts: 1,203
Kudos: 272
Although the first pulsar, or rapidly spinning collapsed star, to be 07 Apr 2021, 14:01
Kudos
Add Kudos
Bookmarks
Bookmark this Post
This one is absolutely laced with errors of meaning.

Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.


(A) Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.
-a correct sentence would read : "was sighted in the summer of 1967..."
-the placement of 'to be sighted' right after the comma distorts the meaning because now we get the impression that the star 'was in the summer'

(B) Although not announced until February, 1968, in the summer of 1967 graduate student Jocelyn Bell observed the first pulsar, or rapidly spinning collapsed star, to be sighted.
-one does not announce a prepositional phrase

(C) Although observed by graduate student Jocelyn Bell in the summer of 1967, the discovery of the first sighted pulsar, or rapidly spinning collapsed star, had not been announced before February, 1968.
-one does not observe the discovery of the first sighted pulsar, but the pulsar itself

(D) The first pulsar, or rapidly spinning collapsed star, to be sighted was observed in the summer of 1967 by graduate student Jocelyn Bell, but the discovery was not announced until February, 1968.
CORRECT

(E) The first sighted pulsar, or rapidly spinning collapsed star, was not announced until February, 1968, while it was observed in the summer of 1967 by graduate student Jocelyn Bell.
-'while it was observed' is blasphemy
User avatar
CrackverbalGMAT
User avatar
Major Poster
Joined: 03 Oct 2013
Last visit: 19 Nov 2025
Posts: 4,844
Own Kudos:
8,945
 [1]
Given Kudos: 225
Affiliations: CrackVerbal
Location: India
Expert
Expert reply
Posts: 4,844
Kudos: 8,945
 [1]
Although the first pulsar, or rapidly spinning collapsed star, to be 11 Jan 2022, 06:33
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968.

A. Although the first pulsar, or rapidly spinning collapsed star, to be sighted was in the summer of 1967 by graduate student Jocelyn Bell, it had not been announced until February, 1968. Since there are multiple singular antecedents, it is not clear what “it” refers to.

B. Although not announced until February, 1968, in the summer of 1967 graduate student Jocelyn Bell observed the first pulsar, or rapidly spinning collapsed star, to be sighted. “Although not announced until February” needs to be followed by who or what was not announced.

C. Although observed by graduate student Jocelyn Bell in the summer of 1967, the discovery of the first sighted pulsar, or rapidly spinning collapsed star, had not been announced before February, 1968. “Although observed by graduate student Jocelyn Bell in the summer of 1967” needs to be followed by who or what was not observed.

D. The first pulsar, or rapidly spinning collapsed star, to be sighted was observed in the summer of 1967 by graduate student Jocelyn Bell, but the discovery was not announced until February, 1968. The structure makes the intended meaning very clear.

E. The first sighted pulsar, or rapidly spinning collapsed star, was not announced until February, 1968, while it was observed in the summer of 1967 by graduate student Jocelyn Bell. The use of “while” makes it seem like the sighting was not announced as it was being sighted.

- Nitha Jay
User avatar
sidhusan
User avatar
Joined: 06 Jun 2023
Last visit: 16 Jan 2024
Posts: 11
Own Kudos:
1
Given Kudos: 210
Location: Sri Lanka
Schools: Tepper '27
GMAT 1: 710 Q49 V38
GPA: 2.22
Schools: Tepper '27
GMAT 1: 710 Q49 V38
Posts: 11
Kudos: 1
Although the first pulsar, or rapidly spinning collapsed star, to be 12 Sep 2023, 05:27
Kudos
Add Kudos
Bookmarks
Bookmark this Post
Is the use of "had not been announced until feb 1968" wrong? Although it is not the earlier than the sighting, it is still earlier than feb 1968.
User avatar
GMATNinja
User avatar
GMAT Club Verbal Expert
Joined: 13 Aug 2009
Last visit: 18 Nov 2025
Posts: 7,443
Own Kudos:
69,783
 [1]
Given Kudos: 2,060
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:
GMAT Club Tests Forum Quiz
Expert
Expert reply
GMAT 2: 800 Q51 V51
GRE 1: Q170 V170
GRE 2: Q170 V170
Posts: 7,443
Kudos: 69,783
 [1]
Although the first pulsar, or rapidly spinning collapsed star, to be 01 Oct 2023, 13:36
1
Kudos
Add Kudos
Bookmarks
Bookmark this Post
sidhusan
Is the use of "had not been announced until feb 1968" wrong? Although it is not the earlier than the sighting, it is still earlier than feb 1968.
Show more
We attempted to address the past perfect in our original explanation and again in this follow-up post. Check those out, and let us know if you still have questions!
avatar
TheUltimateWinner
avatar
Schools: Harvard '24 Judge '23 LBS '24 McCombs '24 Mendoza Tepper '24 Ross '24 Cox Marshall '24 Fisher Kelley '24 Jones McDonough '24 Owen '24 Terry BU Simon '24 Katz GWU Mason Babson Gabelli Foster '24 Goizueta '24 Scheller Stern '23 CBS '23 Booth '23 Haas '25 Wharton '25 Stanford '26 Johnson'23 Fuqua '23 Kellogg '23 Kenan-Flagler'23 INSEAD Aug 22 intake Olin '23 Said '23 Sloan '23 Carey Arizona "22 Yale '23 UC Davis Madison '23 Anderson '23 Carroll Carlson '23 Darden '23
Posts: 2,489
Kudos: 2,387
Although the first pulsar, or rapidly spinning collapsed star, to be 01 Nov 2023, 17:00
Kudos
Add Kudos
Bookmarks
Bookmark this Post
JonShukhrat
varotkorn


My question comes from:
Quote:
OA: BY 1999, astronomers had discovered 17 nearby stars that are orbited by planets about the size of Jupiter
Quote:
OA: The personal income tax did not become permanent in the United States until the First World War; BEFORE that time the federal government had depended on tariffs as its main source of revenue.

According to choice C: ...the discovery of the first sighted pulsar had not been announced BEFORE February, 1968.

Choice C. is similar to the examples above where "February, 1968" is the later event and "HAD NOT BEEN ANNOUNCED" is the earlier event.

Why is HAD NOT BEEN ANNOUNCED in choice C. wrong, whereas OAs above are right?



Hi varotkorn

Not so long ago I did small research on the use of the Past Perfect tense (PP) in sentences with “before”. It might be interesting for you too. Your thoughts are welcome as well.

There is quite interesting and simple rationale behind such use. You may have read that “before” already clarifies the sequence of events, and therefore PP is redundant. Well, not always so. There are two things to consider first:
I. whether two events are compatible or mutually exclusive;
II. whether the earlier event is non-continuous;

Case 1: Compatible events – events that may happen together.

Could you take a look at the two examples from GMATGuruNY below (here) and tell the difference in meaning?

1. Before John became a painter, he studied music.
2. Before John became a painter, he HAD studied music.

The first merely states which action started first, but doesn’t clarify whether John stopped studying music before becoming a painter. He may have very well continued to study music even after becoming a painter. i.e, he could do both. The second, in contrast, tells that John STOPPED studying music before becoming a painter. Another set of examples:

3. Before John became a painter, he left his town.
4. Before John became a painter, he HAD left his town.

The third sentence is different from the previous two in that - it already clarifies that “the action of leaving” was already over before John became a painter. In other words, both events such as “became” and “left” could NOT happen together. The reason behind is that “leave” is a non-continuous action while “study” is not. I mean, the event “leave” happens at one point in time - we either leave or stay. When we leave, we leave, so there is no need for PP to show that we left the town. On the contrary, the event “study” may continue for any period – days, weeks, or years - so we need PP to show that the study is over. Therefore, PP in sentence 4 is pointless.

In short: non-continuous verbs usually don't need PP in such cases, whereas the reverse is true for continuous ones. By the way, I made up the terms “non-continuous” and “continuous” just to deliver my point. I mean, you already know the difference between “hear” and “listen”, or between “see” and “watch”, right? The same story.
__________________________________________________________________________________________

Case 2: Mutually exclusive events – events that can NOT happen together, or the start of the one denotes the end of the second.

Try to analyze the difference in the meaning:

5. Before John became the president of the country, he served as a state senator.
6. Before John became the president of the country, he HAD served as a state senator.
7. Before John became the president of the country, he owned a multibillion dollar company.
8. Before John became the president of the country, he HAD owned a multibillion dollar company.

“Becoming the president” and “serving as a state senator” are mutually exclusive events. John could NOT do both. Logically, when he became the president, he already stopped serving as a state senator. Hence, PP in sentence 6 is pointless. Note that when events are mutually exclusive, whether the verb is non-continuous usually doesn’t matter. i.e., the verb “serve” is continuous, but PP is needless anyway.

However, John could “become the president” and still continue to “own a multibillion dollar company”, as in sentence 7. These events are compatible, so we need PP if we wish to show that he stopped owning such company, as in sentence 8.

In short: first we need to check whether the events are mutually exclusive. If yes, then no need for PP. If no, then further check whether verbs are non-continuous. If yes, then no need for PP. If no, then use or omit PP, depending on the meaning we want to convey.

__________________________________________________________________________________________


Now, you yourself can analyze why PP is valid or invalid in the following official problems you asked about:

1. The personal income tax did not become permanent in the United States until the First World War; before that time the federal government had depended on tariffs as its main source of revenue. (why PP is correct?)

2. The discovery of the first sighted pulsar, or rapidly spinning collapsed star, had not been announced before February, 1968. (why PP is wrong?)


The spoiler is in the following post.
Show more
JonShukhrat
What an explanation, bro! Just kudos :heart
   1   2   3 
Moderators:
GMATNinja
GMAT Club Verbal Expert
7443 posts
GMATNinjaTwo
GMAT Club Verbal Expert
231 posts
miag
188 posts