Changes in the composition of the light of a supernova—an exploding

(E)

Reveal not only A but also B is the correct form.

In other choices ||ism is broken by saying "Not only reveal A but also <needed>"

I think the options B, C and D breaks the parallelism rule. Not only X but also Y, X and Y should be parallel. A and E both have parallel X and Y but they A is incorrect due to its faulty S-V agreement (Changes .... reveals), Hence I picked E
Pls correct me if I am wrong
PS

I was confused with subject here, not sure whether it was "Changes" or "an exploding star".

Subject will not be in prep phrase.

In this example on what grounds we decide that "an exploding star" is not a subject.

Thanks in advance for the help.

Rgds,
Ram

Hi jrk23,

Here are 3 ways to decide:

1) Punctuation

A pair of dashes is similar to parentheses, or 2 commas. " - an exploding star -" just serves to define what a supernova is.

You are correct that "Subject will not be in prep phrase".

"in the composition of the light of a supernova - an exploding star -" is a common tactic by the test writers to distract you from the subject, "Changes"

For subject-verb issues, ignore modifiers such as this and simplify it to "Changes reveal".


2) Structure

If "reveals" is the verb for "an exploding star", then "Changes" would be hanging without a verb. A common error is to have no main verb for a subject.


3) Meaning

"Changes reveal" fits better with the intended meaning.

Is it the star ITSELF that reveals the chemical elements in the explosion and speed of expanding the outer layers?

Or is it the changes in the composition of light?

Subject in this sentence is “Changes” which is in plural form. So, it doesn’t get along with singular “reveals”. Hence, A and B are out. In answer choice C, “speed of expansion” should replace “speed of expanding”. “not only” is used wrongly in Choice D. It should follow “reveal”. “not only” preceding “reveal” means it is just not only revealing but also doing something else. E has correct Subject-verb agreement and the use of adverb. Hence, E is the answer

Subject in this sentence is “Changes” which is in plural form. So, it doesn’t get along with singular “reveals”. Hence, A and B are out. In answer choice C, “speed of expansion” should replace “speed of expanding”. “not only” is used wrongly in Choice D. It should follow “reveal”. “not only” preceding “reveal” means it is just not only revealing but also doing something else. E has correct Subject-verb agreement and the use of adverb. Hence, E is the answer.

Changes in the composition of the light of a supernova--an exploding star--reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas.

(A) reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas —> “changes” is plural, so “reveals” is wrong

(B) reveals not only what chemical elements are in the explosion but also the speed at which the outer layers of stellar gas are expanding —> same as A

(C) not only reveal the chemical elements in the explosion but also the speed of the expanding outer layers of stellar gas —> wrong: not only “reveal” ... but also “the speed”

(D) not only reveal what chemical elements are in the explosion but also the speed of the outer layers of stellar gas when they are expanding—> wrong: not only “reveal” ... but also “the speed”

(E) reveal not only the chemical elements in the explosion but also the speed at which the outer layers of stellar gas are expanding—> correct: not only “the elements” ... but also “the speed”

Main Issues:

1) Correct Idiom: "Not only X but also Y"
2) Subject Verb agreement

(A) reveals not only the chemical elements in the explosion but also the speed of expanding the outer layers of stellar gas - Wrong: SV 2) Meaning distortion

(B) reveals not only what chemical elements are in the explosion but also the speed at which the outer layers of stellar gas are expanding - Wrong: SV

(C) not only reveal the chemical elements in the explosion but also the speed of the expanding outer layers of stellar gas - Wrong: Parallelism issue

(D) not only reveal what chemical elements are in the explosion but also the speed of the outer layers of stellar gas when they are expanding - Wrong: Parallelism issue 2) Meaning distortion

(E) reveal not only the chemical elements in the explosion but also the speed at which the outer layers of stellar gas are expanding - Correct

Changes is plural
Reveals is plural form. Why is everyone saying reveals is singular form? i am very confused by that.

Hi schooliscool, that's the funny thing about English: For the most part, Nouns are plural when they end in "s" while Verbs are singular when when they end in "s".

Since reveals is a verb that ends in "s", reveals is singular (reveal would be plural).

I narrowed it down to C and E quickly.

I chose C because I thought "are expanding" was wrong. Wouldn't just "expand" make more sense? I understand the //ism error in C now, but I don't understand how "Are expanding" is ok. Any help on this would be very appreciated!

Big boss, thanks for your replies!