The largest of all the planets, not only is Jupiter three times so massive as Saturn, the next larger planet, but also possesses four of the largest satellites, or moons, in our solar system.
(This question is from Official Guide. Therefore, because of copyrights, the complete question cannot be copied here. The question can be accessed at GMAT Club)
The sentence starts with an adjectival phrase “The largest of all the planets”. After reading this phrase, we expect to come across the noun that this adjective modifies. However, the sentence then reads “not only is Jupiter..”.
This is the first error in the sentence. The beginning modifier should be immediately followed by the noun that it modifies.
The second error is the incorrect use of the idiom “so..as”. This construction is only used to communicate negative comparison. The construction “as..as” is used in both positive and negative comparisons. For example: the first three sentences below are correct; the fourth one is incorrect.
- Tom is as nice as Joe.
- Tom is not as nice as Joe.
- Tom is not so nice as Joe.
- Tom is so nice as Joe. (Incorrect)
The third error in the sentence is lack of parallelism. While the “not only” part has both the subject and the verb (Jupiter is), “but also” has only verb. Therefore, these two elements are neither logically nor grammatically parallel.
The fourth error in the sentence is the use of “the next larger”. This phrase is unidiomatic. The correct version is “the next largest”, which is perfectly fine in the context of the sentence since Jupiter is given as the largest of all the planets.
The sentence, thus, has four errors.
(A) Incorrect. For the errors described above.
(B) Incorrect. This option contains the first and third errors of the original sentence.
(C) Incorrect. For the following reasons:
- No verb for the subject “Jupiter” in the “not only” part.
- Lack of parallelism – The part after “not only” is an adjective phrase but the part after “but also” is a verb phrase. More importantly, they are not logically parallel i.e. you cannot replace one element with the other element in the sentence.
(D) Correct. This option corrects all the errors in the original sentence without introducing any new errors.
(E) Incorrect. For the following reasons:
- Lack of Parallelism – Same error as error 2 of option C
- The use of “so..as” is incorrect here as explained in the sentence analysis
- The use of “the next larger” is incorrect as explained in the sentence analysis.