Either -Or parallelism

[shalini.mishra89]

Hi there ,
I am having a tough time understanding the either -or parallelism structure . Could you please throw some light on it .

Following is a question from MGMAT for reference :

Many of today’s mathematicians use computers to test cases that are either too time-consuming or involve too many variables to test manually, allowing the exploration of theoretical issues that were impossible to test a generation ago.

A) are either too time-consuming or involve too many variables to test manually, allowing the exploration of
B) either take too much time or involve too many variables to be tested manually; allowing the mathematicians to explore
C) would either take too much time or involve too many variables to test manually, allowing them to explore
D) would either be too time-consuming or would involve too many variables to test manually; this capability allows the mathematicians to explore
E) take too much time or variables to test manually; this capability allows the mathematicians to explore

Thanks !

[RonPurewal]

What, specifically, do you understand?
What, specifically, don't you understand?
In which answer choice(s)?

Thanks.

[MeghaV725]

Hi Ron,

Can u please elaborate on the usage of "would" in option C? Can this be used as a deal breaker in this question?

[RonPurewal]

Hi Ron,

Can u please elaborate on the usage of "would" in option C? Can this be used as a deal breaker in this question?

Describing hypothetical, contrary-to-fact cases is a routine use of "would". No problem there.

[RonPurewal]

E.g.
Bus route #51 is important to the neighborhood's residents, who, without it, would have no easy or inexpensive way to get to the airport.
Here we must use "would", because we're definitely describing something contrary to fact. (I.e., "They have no easy way..." is false, because the bus route is there.)

In this problem, either tense is sensible:
• "... that take too long...": The mathematicians have tried manual testing. It takes too long.
• "... that would take too long...": They haven't actually tried it, but they know (e.g., from experience) that it would take too long if they did try.

[MeghaV725]

Thanks Ron, I got your point.

[tim]

:)

[RonPurewal]

Remember, step 1 of EVERY sentence correction problem is "Understand exactly what the words are supposed to say".

[ManikS687]

In choice C, isn't the usage of pronoun "them" vague as it can refer to nearest noun - variables or other nouns - computers or mathematicians?

How is it clear that "them" is referring only to the "Mathematicians"? Is here any rule of grammar?

[RonPurewal]

the intended meaning of a pronoun should always be perfectly clear in context. remember—"pronoun ambiguity" is NOT tested on this exam!

for ANY pronoun, you should ALWAYS know exactly what the pronoun SHOULD stand for. if that noun is present in the sentence (and matches the pronoun in terms of singular/plural), then it's fine—regardless of whether there are other nouns in the sentence.

[sssss984]

what does 'allowing' here modify?
I thought '-ing' form should always modify the subject of the preceding clause. can anybody help me with this?

[Sage Pearce-Higgins]

Check out the Modifiers chapter of the SC strategy guide. "-ing" words have a number of different functions as modifiers. In this case, 'allowing' is modifying the whole preceding clause: it's showing a consequence of the mathematicians' use of computers.

[ZhuomengG709]

By the way, could you explain why choice (D) isn't correct?

[Sage Pearce-Higgins]

Answer D can be eliminated for a parallelism error. Look carefully at what follow the words 'either' and 'or' and see how that connects with the root phrase.