Parallelism and Ellipsis

[Guest]

Scenario A: Which one would you choose? Is one more correct than the other? Is it a rule that if the second element can reuse the first part, it is correct?
(A1) John was interested in English but not Economics
(A2) John was interested in English but not in Economics

Scenario B: Which one would you choose? Are they all correct?
(B1) The speed of the car that Billy drives is greater than the speed of the car that Joe drives
(B2) The speed of the car that Billy drives is greater than the speed of the one that Joe drives
(B3) The speed of the car that Billy drives is greater than the speed of that that Joe drives
(B4) The speed of the car that Billy drives is greater than that of which Joe drives
(B5) The speed of the car that Billy drives is greater than that which Joe drives
(B6) The speed of the car that Billy drives is greater than that of Joe's
(B7) The speed of the car that Billy drives is greater than Joe's

[Sudhan]

Scenario A: Which one would you choose? Is one more correct than the other? Is it a rule that if the second element can reuse the first part, it is correct?
(A1) John was interested in English but not Economics
Incorrect
(A2) John was interested in English but not in Economics
Correct

Scenario B: Which one would you choose? Are they all correct?
(B1) The speed of the car that Billy drives is greater than the speed of the car that Joe drives
Correct
(B2) The speed of the car that Billy drives is greater than the speed of the one that Joe drives
Correct
(B3) The speed of the car that Billy drives is greater than the speed of that that Joe drives
Correct
(B4) The speed of the car that Billy drives is greater than that of which Joe drives
Incorrect
(B5) The speed of the car that Billy drives is greater than that which Joe drives
Incorrect
(B6) The speed of the car that Billy drives is greater than that of Joe's
Incorrect
(B7) The speed of the car that Billy drives is greater than Joe's
Incorrect


Thanks

[Guest]

sudhan, will you please explain your thought process and logic to arrive at the answer.

[RonPurewal]

Scenario A: Which one would you choose? Is one more correct than the other? Is it a rule that if the second element can reuse the first part, it is correct?
(A1) John was interested in English but not Economics
(A2) John was interested in English but not in Economics

Scenario B: Which one would you choose? Are they all correct?
(B1) The speed of the car that Billy drives is greater than the speed of the car that Joe drives
(B2) The speed of the car that Billy drives is greater than the speed of the one that Joe drives
(B3) The speed of the car that Billy drives is greater than the speed of that that Joe drives
(B4) The speed of the car that Billy drives is greater than that of which Joe drives
(B5) The speed of the car that Billy drives is greater than that which Joe drives
(B6) The speed of the car that Billy drives is greater than that of Joe's
(B7) The speed of the car that Billy drives is greater than Joe's

a1 and a2 are both acceptable.
there's no left-hand marker for parallelism (i.e., it's not a two-part structure like 'not only ... but also'), so we can start the parallelism wherever it's convenient to fit the structure of the sentence.
so a1 can be parsed as
John was interested in English but not Economics, where the boldfaces are parallel,
and a2 can be parsed as
John was interested in English but not in Economics, where the boldfaces are also parallel.

if you have a double parallel marker, then the strictures of parallelism are more severe. see if you can parse these and see why they're correct or incorrect:
correct: john was interested not only in economics but also in english.
correct: john was interested in not only economics but also english.
incorrect: john was interested not only in economics but also english.
incorrect: john was interested in not only economics but also in english.

of a1 and a2, i like a1 better, because it's more concise; the second 'in' is generally frowned upon in short, completely unambiguous sentences such as that one.

--

b4-b7 are all wrong. in b4-b5, 'that' has to mean speed, but the meaning of the sentence would be absurd (you can't drive a speed). in b6-b7, the possessive is unacceptable, since there's no possessive for billy (i.e., nothing is indicated as "billy's").

b3 is wrong too, because 'that that' just isn't happening in formal written english. you can do 'had had' - because that's the only possible past perfect form of 'to have' - but i can't think of any other repeated words that are acceptable.

b1-b2 are ok, but are excessively wordy, to the point where they qualify as terrible writing. here are a couple of possible revisions:
the car driven by billy is faster than that driven by joe (note the use of participles -- 'the X that Y VERBs' should normally be avoided, in favor of 'the X VERBed by Y'
billy's car is faster than joe's --> the ultimate in concision, although only if billy and joe actually own the cars they drive