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GMAT Idioms of Comparison

UPDATE: You can find this blog and others about idioms in our new GMAT Idiom eBook!

Business is all about comparisons — which brand or option or product is cheaper?  faster? more reliable? safer? a better investment?  etc. etc.  Because of this, the GMAT loves comparisons, and loves to explore them in Sentence Correction.   The idioms used in comparisons are endlessly varied and subject to numerous colloquial errors, so this is a veritable treasure trove for the Sentence Correction to explore.

In previous posts, I discussed:

a. the “like” vs. “as” distinction

b. a tricky exception to the “like” vs. “as” distinction

c. comparisons involve “so”

d. comparisons involving quantities

e. a quirky comparison idiom

This article takes a look at the wide variety of idioms used in comparisons.


Comparisons to the subject of the sentence

The following forms can be used when one term of the comparison is the subject of the sentence, a very common form on GMAT Sentence Correction.

more than

more (adjective) than

different from

in contrast to A, B

unlike A, B

compared to A, B

The first involves a few variations.  If the verb is intransitive (i.e. it takes no direct object), then we can use the construction A [verb] “more than” B.

1) Alison sings more than Bertrand.

Here, the phrase “more than” can be replaced with any comparative adverb phrase.

2) Charles sleeps more deeply than David.

3) Elizabeth laughs more heartily than Francine.

In any of those three, it would also be correct to stick a verb after the word “than.”

1a) Alison sings more than does Bertrand.

2a) Charles sleeps more deeply than David does.

These sentence are fine either with or without the verb after the word “than.”

If the verb is transitive (i.e. it takes a direct object), then we use the construction A [verb] “more” [direct object] “than” B or A [verb] [direct object] [comparative adverb] “than” B.

4) Gerald has published more articles than Henry.

5) Iphigenia follows baseball more avidly than does James.

6) Ken gives more money to charity than does Lawrence.

In #4, we could have added a verb after “than” — that also would have been correct.  In #5 and #6, the verb after “than” is absolutely necessary to resolve ambiguity.  Consider them without this second verb:


Does Iphigenia follow James as well as baseball? Does Ken give money to Lawrence as well as to charity?  The absence of a verb creates ambiguity: is the object of “than” in parallel with the subject or the direct object?  This ambiguity did not arise in #4, because Gerald could not possibly “publish” Henry — because of the context, Henry can only be parallel to the subject.   Without the verb, though, the other two are ambiguous, and the GMAT Sentence Correction hates ambiguity.

The adjective “different” idiomatically take the preposition “from.”  The construction “A is different from B” contrasts A with B, but it’s not very interesting in and of itself.  If we add an “in that” clause, then the sentence becomes much more sophisticated:

7) The final movement of BrahmsFourth Symphony is different from the final movement of virtually every other symphony in the classical repertoire in that it is a passacaglia.

The next three idioms all act as modifiers to the subject:

8) Compared to the Mona Lisa, Leonardo‘s Lady with an Ermine has a smile that is far less famous but just as enigmatic.

9) In contrast to his depraved predecessor Caligula, Claudius (10 BCE – AD 54) was a particularly just and efficient ruler who enriched the empire with extensive public works.

10) Unlike a maze, a labyrinth has only one path from entrance to goal and thus involves no choices at all: its object is inner reflection and mystical contemplation, rather than the rational puzzle-solving that a maze demands.

Because all three of these are modifiers, all three are vulnerable to problems involving the modifier touch rule.  For example, consider:


This is a classic GMAT Sentence Correction mistake pattern — here, the grammar suggests we are comparing the painting The Mona Lisa to the artist Leonardo da Vinci.  The GMAT loves to construct incorrect SC answer choices of this form: misplaced modifiers and violations of the Modifier Touch Rule for comparative modifiers!  This is one of the most common mistake patterns on the Sentence Correction section.


Rather vs. Instead

Sentence #10 was a “two-fer” — in addition to the “unlike” idiom, we also had an example of the “rather than” than idiom.  Both rather and instead can be used as adverbs, meaning “on the contrary,” but these constructions don’t appear on the GMAT.  The GMAT focuses on rather than vs. instead of.  The latter is a compound preposition, and, as such, could only take a noun as its object.  By contrast, rather than can act as either a preposition (taking a noun) or a subordinate conjunction (followed by a full clause).  Instead of could only put nouns in parallel, but rather than can put nouns or verbs or entire actions in parallel.  In general, the GMAT seems to avoid the situations in which a correct use of “instead of” would be allowed, and seems to use “instead of” only as an incorrect choice for “rather than.”

11) She simply bought a condo in Boston, rather than pay for a hotel room for several months.

In that sentence, the verbs “bought” and “pay” are in parallel.  Notice that since the latter action is hypothetical, it is in the subjunctive.  If this were the correct choice in a Sentence Correction question, a typical incorrect choice would be:




The proper idioms here are distinguish between A and B and distinction between A and B, distinguish A from B and the distinction of A from B.  The subtle differences between these are not worth exploring — the GMAT Sentence Correction will not split hairs about this.   In all of these constructions, both A and B have to be either nouns or something that acts as a noun — a gerund or a substantive clause.   Here’s an example with gerunds:

12) Many ethicists do not distinguish between telling an outright lie and intentionally concealing some part of the true.

Here’s an example with substantive clauses.

13) The distinction of what the eye sees from what the brain perceives is, for all practical purposes, meaningless.



Both of these idioms are correct: in contrast with and in contrast to.  The construction “as contrasted with/to” is not acceptable.  Both “with” and “to” are prepositions, so again, they can be followed by a noun, or by something that acts as a noun — a gerund or a substantive clause.  Here’s an example with a gerund.

14) In contrast to sending an email, writing a text message seems like such an evanescent form of communication.

The GMAT Sentence Correct does not like the structure [preposition][noun]participial phrase] — that’s too much “action” for a preposition to contain.


We would have to change that first action entirely to a noun (e.g. “Dante’s assignment of his enemies to hell” = awkward!), or have to use a subordinate conjunction contrast word, such as “whereas“:

15b) Whereas Dante assigned his enemies to hell, Joyce, in Finnegans Wake, celebrates and has fun even with the words of his harshest critics.


Three particularly sophisticated idioms for comparisons

Finally, we reach the heights of Parnassus, some of the most sophisticated language you could see on the GMAT Sentence Correction.

same to A as to B

just as P, so Q

X is to Y what A is to B

The first is a remarkably succinct construction.  In this, A and B are most often people, and the subject is some sort of experience.

16) Are the emotional inflections in the human voice the same to a dog as to a baby?

Notice that we could repeat the subject & verb after “as” — “as they are to a baby” — this would also be correct, but less succinct.

In the second idiom, P and Q are full [noun]+[verb] clauses, describing actions we are comparing.

17) Just as Darwin‘s ideas “dethroned” humans from their supposed unique place among biological entities, so Freud‘s ideas subordinated the conscious subject to much more powerful forces of the Unconscious.

18) Just as the Sun is the center of eight planets and numerous smaller satellites, so Jupiter holds in orbit four large moons and dozens of smaller moons, forming a “solar system in miniature.

Perhaps the most sophisticated is the final idiom, which compares two relationships — it compares the relationship between X & Y to the relationship between A & B.

19) Franklin was to many of the younger members of the Continental Congress, such as Jefferson and Hancock, what Niels Bohr was to the founders of Quantum Mechanics.

20) The ancient Celtic stories of Arthur were to Malory’s Le Morte D’Arthur what Muslim tales of the Mi’raj were to Dante’s Divine Comedy.



Know the idioms given in bold in this post.  As always with idioms, read, read, read!   Search for the idioms in this post in context.  You understand English best when you understand it in context.


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