X is one of the best books that are written by black Americans
- Many best books written by many black Americans and X is one among those books.

X is one of the best books that is written by black Americans
-X is written by more than one black American.

X is one of the best books written by black Americans
- If I'm not wrong is not this structure ambiguous as this can mean either of the above two sentences. If a sentence is having such structure should we ignore this part and look for other errors.

Be careful! The third version here is actually the best!

Assuming that we mean that X is one of the best among all of the books written by black Americans, then C is both clear and concise (as well as perfectly grammatical), aka a WINNER.

A is awkward in that it says "books that are written," in present tense! This is strange, as it shows that this collection of books is being created right now, and X is one of the best. It would be hard to judge a book that is currently being written, must less compare it to other books that are currently being written. The past tense would help a bit, but the simple past participle "written" is best.

Your second version I would throw out, because the "that" seems to describe "books," and the "is" does not agree with "books."

You may wish to check the concision patters at the beginning of our SC strategy guide. Note that we wish to reduce the number of times we use "to be" verbs (is, are, etc.). This helps us to see why your third version is best here.

I could not post my Q properly. I was not looking for correct ans among those. I'm reposting it again.

X is one of the best books written by black Americans
X is one of the best books written by a black American

For the above structures what should be the correct interpretation.

books are written by b.a or X is written by b.a. Or it depends on the sentence. My understanding was black Americans modifies the books. This is a part of a SC where second one is interpreted as X is written by b.a. and this is OA.

I have 2 follow up general question, not sure which one is right.


1a.He is one of the persons who make money.
or
1b.He is one of the persons who makes money.

2a.This is one of the cars that run on hydrogen.
or
2b.This is one of the cars that runs on hydrogen.

Please explain. Thanks in advance.

I think what you are asking is whether "written by..." modifies "books" or "X" (this particular book) or "one"?

I think the default interpretation has to be that "written by..." modifies "books," because noun modifiers typically must touch the modified noun. If the intended meaning is that X is written by a Black American, and it is among the best of all such books, then I think the 2nd sentence is best. The plural "Black Americans" in the 1st sentence introduces confusion--are we only considering books with more than one author?

I hope that addresses your concern. I have a feeling that I would need to see the rest of the sentence you have in mind to be entirely sure about the question intent.

_________________
Emily Sledge
Instructor
ManhattanGMAT

Your question has to do with whether the verb should be plural (to match the immediately preceding noun, persons or cars) or singular (to match one). Following my logic above, the "who" and "that" relative clauses modify the immediately preceding noun. A grammar purist might even note the lack of a comma, an option with the "who" clause, as evidence that the relative clause is "stuck to" the noun before it! By this logic, the correct options are 1a. and 2a. {Side note: the GMAT would prefer "people" to "persons."}

HOWEVER, there is a lot of disagreement on this. It is very common for the relative clause to use a singular verb, matching "one." Frankly, I think most native speakers use whichever sounds best, depending on the overall context of the sentence. As such, this is not going to be something that the GMAT tests, so hunt for other splits in the very unlikely event that you run across this issue.

Furthermore, when the phrase containing one is introduced by "the," the verb in the relative clause must be singular: Gunther is the only one of the cats who has (not have!) been neutered.

_________________
Emily Sledge
Instructor
ManhattanGMAT

Great. Thank you very much.

: )

Actually this is part of GMATPrep Q. I took it from this forum. As you mentioned default interpretation of this should be 'written by' modifies 'books', I also was under that impression. If you see the following problem for which OA is E 'written by' modifies 'Cane'. I agree this is the best choice available but the point is we can not eliminate choices based on this.

A mixture of poems and short fiction, Jean Toomer's Cane has been called one of the three best novels ever written by Black Americans—the others being Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man.
A. Black Americans—the others being Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man
B. Black Americans—including Native Son by Richard Wright and Invisible Man by Ralph Ellison
C. a Black American—including Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man
D. a Black American—the others being Richard Wright, author of Native Son, and Ralph Ellison, author of Invisible Man
E. a Black American—the others being Richard Wright's Native Son and Ralph Ellison's Invisible Man

If I saw this on the test, I probably wouldn't use that opening split to decide. You could argue either way. But there are other ways to get to the right answer on this one. :)

_________________
Stacey Koprince
Instructor
Director of Online Community
ManhattanGMAT