The fact that “dark matter” accounts for over 95 percent of the matter

Can't understand the last is/are, do you know of any similar question i can refer to??

Using POE :

Subject of first IC is "The fact", so we need a singular verb "Has been" and not plural verb "Have been". Eliminate D and E.

When we see second IC after "but", we can see the SV disagreement. Subject of the second is a clause "What is........", and this means we are talking about something

singular. When clause becomes the subject of the sentence, it is considered "singular". Eliminate A and C.


(A) has been established through analysis of gravity’s effect on light from distant objects, but what is more difficult to determine are

(B) has been established through analysis of gravity’s effect on light from distant objects, but what is more difficult to determine is

(C) has been established through analysis of gravity’s effect on light from distant objects, but what are more difficult to determine are

(D) have been established through analysis of gravity’s effect on light from distant objects, but what is more difficult to determine are

(E) have been established through analysis of gravity’s effect on light from distant objects, but what are more difficult to determine are

hello EpilepticLearner

try this threads, there are a lot of good explanations:

https://gmatclub.com/forum/what-is-foll ... l#p1698723

https://gmatclub.com/forum/the-period-w ... ml#p727032

What he likes much in breakfast is/are an apple, a full glass of milk and two sandwiches.
In my understanding what is modifying the list of three items. So "are" is correct here.

Similarly, in given SC problem, ...but what is/are difficult to determine is/are x, y and z.
I think here what is mentioned for three nouns; therefore, at both places, are is correct.
Whether the clause is singular or plural depends on whether the relative pronoun itself is understood as singular or plural.
Please clear this doubt to avoid further mistakes.

Thanks GKomoku!

Now I am completely agree with your elucidation. And I will keep this in mind while attempting such SC problems.

generis
but "what is more difficult to determine" - is this the substantive clause?

AcetheGMAT2019 , yes, what is more difficult to determine is the substantive clause. (A substantive clause can also be called a noun clause or a nominal clause.)

If you simply wanted confirmation, stop reading. If you want a little more information about substantive clauses, keep reading.

In this post, here, I discuss substantive clauses and provide a link to a good post by Mike McGarry.
Scroll down to the blue bullet point labeled "Substantive clauses."

This grammar article, here contains good examples of the ways in which substantive clauses can function as nouns (subjects, direct objects, appositives, etc.).
The article also lists the words that introduce these clauses. [Ignore the assertion about IF.]
Scroll down to the part titled, "NOUN (OR SUBSTANTIVE) CLAUSES."

Substantive / noun clauses are weird because they contain a verb but are nouns.
Once you get a sense for them, though (by reading examples -- both articles have examples), substantive clauses are pretty easy to spot.

Substantive clauses are almost always singular. (If you have no idea, choose singular!)

The instances in which substantive clauses are plural are unlikely to appear on the GMAT.
I do not recall any such questions.
The article by Mike McGarry discusses the plural exceptions and notes that they are unlikely to show up on the GMAT.
(I have not mined data on this issue. My assertion is impressionistic.)

Hope that helps.

So by the same token, "who is the team members is Peter, Tom and David." and "what makes the team great is the team member's determination, persistence and discipline." are correct?! This is confusing.

@e-gmat
Please explain why C is incorrect?
Is it because "what is more difficult to determine" is a clause, hence it is singular?
Or is it because this dependent clause refers to the subject 'dark matter', which is singular?
I'm having trouble approaching this problem.

VeritasKarishma

Can you pls explain why in A are is not correct in "difficult to determine are ..."

Can someone please explain why the option is not A. My thinking is that "difficult to determine are" suitable for the three things connected by "and" which makes it plural

Hi, You can feel the difference in A & B if you read the sentences this way.

1. The origin, composition, and properties of dark matter is what is more difficult to determine.
2. The origin, composition, and properties of dark matter are what is more difficult to determine.

I believe in these two versions option 1) looks better.

Though, intuitively "are" looks comfortable as per rules of S-V agreement, but on the GMAT, "Noun clauses" are always considered singular.

AkshdeepS GKomoku

Just to clarify,

On the table are a plate, a fork and a knife --> correct as underlined is the main subject
What is on the table is a knife, a fork and a plate --> correct as underlined is the main subject and "a knife, a fork and a plate" is the object in the sentcnce ??

Like I say usually, I'm not pro at this or even good at this but I'll take a hit
what struck to me at glancing the options is the singular and plural tenses in an uneven manner except for B all other option have this issue, for this reason I pick choice B

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