Chapter 10: Parallelism & Comparison Errors
Master two of the most important structural error areas in competitive-exam English: Parallelism and Comparison. This chapter covers basic rules, advanced structures, common traps, comparison of unequal things, correlative constructions and high-level Error Detection patterns.
1. Why Parallelism & Comparison Matter
Parallelism and comparison questions are often difficult because the error is hidden inside the structure of the sentence rather than inside an individual word.
A sentence may contain perfectly correct words but still be grammatically incorrect because the elements being connected or compared are not structurally equivalent.
Keep related grammatical elements in the same form.
Compare logically equivalent things.
either…or, neither…nor, not only…but also
positive, comparative and superlative structures
In higher-level questions, Parallelism and Comparison are frequently mixed with Conjunctions, Adjectives, Adverbs, Pronouns and Modifiers. Therefore, learn the structure rather than memorising isolated examples.
PART A — PARALLELISM
2. What Is Parallelism?
Parallelism means using the same grammatical structure for elements that have the same function in a sentence.
VERB + VERB + VERB
GERUND + GERUND + GERUND
INFINITIVE + INFINITIVE + INFINITIVE
The purpose is to create grammatical balance and clarity.
3. The Basic Parallelism Rule
The first two elements are gerunds, so the third element should also be a gerund.
When words or phrases perform the same grammatical function, keep their grammatical forms parallel.
4. Parallel Nouns
All three elements are nouns.
If the intended structure is a list of qualities, the elements should remain parallel.
5. Parallel Verbs
All three verbs are in the same tense and form.
6. Parallel Adjectives
All three elements are adjectives describing the same subject.
7. Parallel Infinitives
The repeated “to” can sometimes be omitted after the first infinitive when the structure remains clear:
The important issue is not whether “to” is repeated. The important issue is whether the verbs remain structurally parallel.
8. Parallel Gerunds
A gerund-based list should normally maintain the gerund structure.
9. Parallel Clauses
Parallelism is not restricted to individual words. Entire clauses can also be parallel.
Both are structurally acceptable because the two infinitive phrases are parallel.
10. Parallelism with “And”
The elements connected by “and” should normally have equivalent grammatical roles.
11. Parallelism with “Or”
12. Parallelism with “But”
“But” connects contrasting elements, which should maintain the same grammatical function.
13. Correlative Conjunctions & Parallelism
Correlative conjunctions are especially important because they create a strong expectation of parallel structure.
| Pair | Example |
|---|---|
| either…or | Either study hard or practise more. |
| neither…nor | Neither Rahul nor Amit attended. |
| both…and | Both intelligent and hardworking. |
| not only…but also | Not only intelligent but also hardworking. |
| whether…or | Whether you agree or disagree. |
14. Not Only…But Also
The first construction joins two adjectives. Therefore, the second element should also be an adjective.
“What comes immediately after the first half?”
Match the grammatical structure after the second half.
15. Not Only…But Also with Verbs
Here both elements are verb phrases.
16. Either…Or with Parallel Structure
“Study harder” is a verb phrase. “More practice” is a noun phrase. The structure is not parallel.
17. Parallelism in Lists
Lists are common in Sentence Improvement questions. Scan every item after the conjunction.
Circle the conjunction and compare the grammatical structure immediately before and after it.
PART B — COMPARISON ERRORS
18. Degrees of Comparison
| Degree | Purpose | Example |
|---|---|---|
| Positive | No comparison | Rahul is tall. |
| Comparative | Comparison of two | Rahul is taller than Amit. |
| Superlative | Comparison among three or more | Rahul is the tallest student. |
19. Comparative + Than
20. Double Comparative
Avoid combining “more” with a regular comparative ending such as “-er”.
21. Senior, Junior, Superior, Inferior & Preferable
These words are commonly tested because they do not follow the normal “comparative + than” pattern.
22. Prefer vs Would Rather
WOULD RATHER A THAN B
23. Compare Two Things — Use Comparative
When exactly two entities are being compared, the comparative degree is generally appropriate.
The superlative should not normally be used merely because the sentence contains a comparison.
24. One of the + Superlative
“One of the” is followed by a plural noun because the person is one member of a larger group.
25. One of the Best — Verb Agreement
In standard grammar, the relative clause “who work hard” refers to the plural noun “students”.
Don’t automatically make the verb singular merely because “one” appears earlier in the sentence.
26. Comparative + Any Other
When comparing one member with the rest of the same group, “any other” can be important for logical clarity.
This means Rahul is taller than every other student, not Rahul himself.
Rahul is taller than any student in the class can logically include Rahul himself.
“Any other student” removes that ambiguity.
27. Faulty Comparison
A comparison should normally compare equivalent categories.
The sentence compares “salary” with “Amit”, a person.
28. That of / Those of
“That” and “those” are frequently used to avoid repeating a noun in comparisons.
| Original Noun | Replacement |
|---|---|
| singular noun | that |
| plural noun | those |
29. Fewer vs Less
| Fewer | Less |
|---|---|
| Countable plural nouns | Uncountable nouns |
| fewer candidates | less money |
| fewer mistakes | less time |
| fewer books | less information |
30. More vs Most
“More” generally forms a comparative, while “most” generally forms a superlative.
31. Older vs Elder
| Older | Elder |
|---|---|
| General comparison of age | Usually used for family relationships |
| Rahul is older than Amit. | My elder brother lives in Delhi. |
“Elder” is generally not followed directly by “than” in standard exam usage.
32. Farther vs Further
“Farther” is traditionally associated with physical distance, while “further” commonly refers to additional degree, extent or information.
33. Better vs Best
34. As…As
The positive degree is commonly used in equal comparisons.
35. Not So/As…As
Both “not as…as” and “not so…as” occur in standard English, with “not as…as” being especially common.
36. The More…The More
37. The More…The Less
38. Comparative + and + Comparative
Repeated comparatives can indicate a gradual change.
39. No Other + Singular Noun
The construction compares one entity against every other entity in the same group.
40. No Other + Comparative Transformation
These transformation questions are useful for exams.
Understanding these transformations makes it easier to identify errors in Sentence Improvement and Phrase Replacement questions.
41. As Much As vs As Many As
| Expression | Use |
|---|---|
| as much as | Uncountable quantity |
| as many as | Countable plural quantity |
42. Like vs Alike in Comparison
“Alike” is commonly used as a predicative adjective, whereas “like” is commonly used to introduce a comparison.
43. Double Superlative
44. More Than One
“More than one” has a plural meaning but normally takes a singular noun and singular verb.
More than one + singular noun + singular verb.
45. One or More
“One or more” can take a plural noun when the noun itself refers to multiple possible items.
In an Error Detection question, always inspect the noun and the intended meaning before choosing the verb.
46. Comparison of Adverbs
Comparison errors can involve adverbs as well as adjectives.
47. Comparison with Pronouns
Pronouns can make comparison questions deceptively difficult.
In informal English, “than me” is common, but competitive examinations may test the underlying clause structure.
When a comparison is followed by a pronoun, mentally expand the implied clause.
Rahul is taller than I am.
48. The Faulty Comparison Test
Whenever you encounter “than”, stop for two seconds and ask:
49. Parallelism + Comparison Combined
Advanced questions may test both concepts in the same sentence.
All three elements should remain parallel after “designed to”.
50. Advanced Exam Traps
| Trap | Correct Pattern |
|---|---|
| more better | better |
| more easier | easier |
| most tallest | tallest |
| senior than | senior to |
| prefer A than B | prefer A to B |
| would rather A to B | would rather A than B |
| salary higher than Amit | salary higher than that of Amit |
| one of the best student | one of the best students |
| fewer money | less money |
| less candidates | fewer candidates |
| not only X but also Y — unequal forms | Keep X and Y parallel |
| reading, writing and to travel | reading, writing and travelling |
51. Exam-Level Practice Questions
The candidate is not only intelligent but also works hard.
“Intelligent” is an adjective, whereas “works hard” is a verb phrase. The two elements are not parallel.
Correct: The candidate is not only intelligent but also hardworking.
She likes reading books, watching films and to travel.
The first two elements are gerund phrases.
Correct: She likes reading books, watching films and travelling.
This method is more easier than the previous one.
“Easier” is already comparative.
Correct: This method is easier than the previous one.
He is senior than all other officers in the department.
“Senior” takes “to”.
Correct: He is senior to all other officers.
The salary of the manager is higher than the assistant.
The sentence compares a salary with a person.
Correct: The salary of the manager is higher than that of the assistant.
The company aims to reduce costs, improving quality and increase productivity.
The sentence contains infinitive-based parallel elements:
reduce → improve → increase
Correct: The company aims to reduce costs, improve quality and increase productivity.
Of the two proposals, the first is the best.
When comparing two things, the comparative form “better” is generally used.
Correct: Of the two proposals, the first is the better.
Rahul is one of the best student in his class.
“One of the” requires a plural noun.
Correct: Rahul is one of the best students in his class.
The more carefully you analyse the question, better your chances of solving it become.
The construction is:
The more…, the better…
Correct: The more carefully you analyse the question, the better your chances become.
The policies of this bank are better than its competitors.
Policies are being compared with policies, not with competitors.
Correct: The policies of this bank are better than those of its competitors.
The company is interested in expanding its business, entering new markets and to improve its technology.
“Interested in” is followed by gerunds.
Correct: The company is interested in expanding its business, entering new markets and improving its technology.
The new system is more efficient, reliable and it is easier to operate.
The first two elements are adjectives: efficient and reliable.
The third should maintain the same structure.
Correct: The new system is more efficient, reliable and easier to operate.
52. Rapid-Fire Revision: Parallelism
| If you see… | Check for… |
|---|---|
| and | Same grammatical structure |
| or | Same grammatical structure |
| but | Parallel contrasting elements |
| either…or | Parallel structure |
| neither…nor | Parallel structure |
| not only…but also | Parallel structure |
| whether…or | Parallel structure |
| list of three or more items | Same grammatical form |
53. Rapid-Fire Revision: Comparison
| Expression | Correct Pattern |
|---|---|
| Comparative | better than |
| Senior | senior to |
| Prefer | prefer A to B |
| Would rather | would rather A than B |
| Equal comparison | as + adjective + as |
| One of | one of the best students |
| Two things | comparative |
| Three or more | superlative |
| Singular comparison | that of |
| Plural comparison | those of |
| Countable nouns | fewer |
| Uncountable nouns | less |
| More…more | The more…, the more… |
54. The 10-Second Exam Scan
When you see a long Error Detection sentence, don’t try to understand every word first. Use this scan.
COMPARISON: SAME CATEGORY → FAIR COMPARISON
55. Final Master Checklist
- Are the elements joined by a conjunction grammatically parallel?
- Are all items in a list in the same grammatical form?
- Does “not only…but also” maintain parallelism?
- Does “either…or” maintain parallelism?
- Does “neither…nor” maintain parallelism?
- Is the correct degree of comparison being used?
- Is “than” being used with the comparative degree?
- Are special words such as senior, superior and preferable followed by “to”?
- Is a comparison logically comparing equivalent things?
- Should “that of” or “those of” be used?
- Is “one of” followed by a plural noun?
- Is “fewer” being used with countable plural nouns?
- Is “less” being used with uncountable nouns?
- Is the “the more…the more” structure complete?
Parallelism asks: “Are these elements built alike?”
Comparison asks: “Are these things comparable?”
If you train yourself to ask these two questions, a large number of apparently difficult Error Detection questions become much easier.