Logical Comparisons on the ACT English Test: Rules, Examples, & Quiz
Introduction
Imagine being in the middle of the ACT English section, feeling confident, and suddenly encountering a sentence like this: "The fuel efficiency of electric vehicles is superior to gasoline cars." At first glance, it sounds completely natural in everyday conversation. But on the ACT, that sentence is a fatal grammar trap!
Why? Because the sentence compares fuel efficiency (a mechanical attribute) directly to gasoline cars (physical vehicles). You cannot compare an abstract metric to an automobile; you must compare efficiency to efficiency!
Welcome to the world of logical comparisons. On standardized exams like the ACT, SAT, and EST, test-makers deliberately construct comparisons that sound acceptable to the ear but violate logical parallelism. In this definitive guide, we will unpack the golden rules of comparison, dissect pronoun substitutions like that of and those of, provide complete textbook answers for exercises 1 through 10, examine actual ACT test questions, and test your skills with an interactive test-prep challenge!
📌 What is a logical comparison error on the ACT?
A logical comparison in grammar ensures that two or more fundamentally similar entities are compared. On the ACT English test, faulty comparisons occur when an author compares an attribute, possession, or trait to an entire person, object, or place, typically corrected with 'that of,' 'those of,' or possessive apostrophes.
Faulty Entity
Comparing a trait or part to an entire person or object.
That of / Those of
Using singular ('that of') or plural ('those of') pronouns to maintain parallelism.
Elliptical Ambiguity
Omitted words in 'than' clauses that create two competing interpretations.
The 4 Golden Rules of Comparison for ACT English
When tackling comparison questions on test day, look for comparative trigger words such as than, as... as, similar to, different from, and prefer... to. Then verify these four core principles:
Rule 1: Always Compare Parallel Categories (Apples to Apples)
Trait to Trait • Person to PersonMake sure the two sides of the comparison are grammatically and logically equivalent. If you begin by discussing a person's performance or work, you must compare it to another person's performance or work, not the person themselves!
❌ Illogical: "Julia’s characterization of Lady Macbeth was more compelling than Rita." (Compares a characterization to a human being!)
✅ Logical (Possessive): "Julia’s characterization of Lady Macbeth was more compelling than Rita’s."
✅ Logical (Full): "Julia’s characterization of Lady Macbeth was more compelling than Rita’s characterization."
Rule 2: Use "That of" (Singular) and "Those of" (Plural)
Preventing Redundancy While Maintaining LogicRather than repeating the head noun, standard formal English replaces singular nouns with that of and plural nouns with those of.
❌ Illogical Singular: "The wingspread of the wandering albatross is greater than any other bird."
✅ Logical with "That of": "The wingspread of the wandering albatross is greater than that of any other bird."
❌ Illogical Plural: "Lincoln’s accomplishments far exceed any other president."
✅ Logical with "Those of": "Lincoln’s accomplishments far exceed those of any other president."
Rule 3: Eliminate Ambiguous Elliptical Comparisons
Supply the Missing Verb to Clarify Subject vs. ObjectAn elliptical comparison omits words understood by context. If the omission allows two competing meanings, you must add the clarifying subject or auxiliary verb:
⚠️ Ambiguous: "We have known Chen a great deal longer than Anzu." (Did we know Chen longer than Anzu knew Chen, or longer than we knew Anzu?)
✅ Clear Meaning 1: "We have known Chen a great deal longer than we have known Anzu."
✅ Clear Meaning 2: "We have known Chen a great deal longer than Anzu has known her."
Rule 4: Never Drop the Second "As" in Compound Comparisons
"As well as, if not better than"When combining positive (as... as) and comparative (better than) modifiers, colloquial speech often lazily omits the second as. On the ACT, this omission is an automatic error!
❌ Nonstandard: "This year’s soccer team is playing as well, if not better than, last year’s team."
✅ Standard: "This year’s soccer team is playing as well as, if not better than, last year’s team."
Exercise Walkthrough: Correcting Sentences 1–10
Below are complete, textbook-level reconstructions for the chapter exercise. Each problem highlights the original flawed sentence, identifies the grammatical error, and provides the standard formal revision:
❌ Original: Sarah’s test scores arrived by mail two weeks sooner than Jesse.
🔍 Problem: Compares test scores to a person (Jesse). Scores can only be compared to scores.
✅ Model Revision: Sarah’s test scores arrived by mail two weeks sooner than Jesse’s [scores].
❌ Original: Which one of these is more complete?
🔍 Problem: In formal grammar, complete is an absolute state (something is either complete or incomplete); it cannot logically take degrees like more without an adverb like nearly.
✅ Model Revision: Which one of these is more nearly complete?
❌ Original: Bryan amazed even himself by swimming as far, if not farther than, anyone at the school had ever swum before.
🔍 Problem: Omits the second as in the positive comparison (as far as), and fails to exclude Bryan from his own group using else.
✅ Model Revision: Bryan amazed even himself by swimming as far as, if not farther than, anyone else at the school had ever swum before.
❌ Original: Some historians say that Lincoln’s accomplishments in such a relatively short time far exceed any other president.
🔍 Problem: Compares plural accomplishments directly to a human president.
✅ Model Revision: Some historians say that Lincoln’s accomplishments in such a relatively short time far exceed those of any other president.
❌ Original: Shirley’s design for the set of the next musical was obviously more practical than Ruben.
🔍 Problem: Compares Shirley's design to Ruben himself rather than Ruben's design.
✅ Model Revision: Shirley’s design for the set of the next musical was obviously more practical than Ruben’s [design].
❌ Original: Luisa sees movies much more often than her friend Sandra.
🔍 Problem: Does Luisa see movies more often than Sandra sees movies, or does Luisa see movies more often than she sees Sandra?
✅ Model Revision: Luisa sees movies much more often than her friend Sandra does.
✔️ Original: Ernesto enjoyed the literature of the Romantic Period as much as, if not more than, the literature of the Renaissance.
🔍 Analysis: Correct as written! It retains both as words (as much as) and compares literature to literature.
✅ Evaluation: C (Correct).
❌ Original: Hercules had to perform twelve labors, each of which was more impossible than the previous one.
🔍 Problem: Impossible is an absolute state; something cannot be "more impossible" than impossible.
✅ Model Revision: Hercules had to perform twelve labors, each of which was more difficult than the previous one (or: more nearly impossible).
❌ Original: Katherine agrees with the literary critics who call Sonnet 18 Shakespeare’s most perfect poem.
🔍 Problem: Perfect is an absolute condition; in formal usage, a poem cannot be "most perfect."
✅ Model Revision: Katherine agrees with the literary critics who call Sonnet 18 Shakespeare’s best poem (or: most nearly perfect poem).
✔️ Original: Jason’s bike is even lighter than Daniel’s.
🔍 Analysis: Correct! The apostrophe -s in Daniel’s cleanly stands for Daniel’s bike, maintaining logical parallelism.
✅ Evaluation: C (Correct).
Real ACT Test Question Breakdown & Analysis
Review the six authentic ACT test question patterns featured in the official exam excerpts below. Notice how the test-makers reuse the exact same mechanical traps:
ACT Logical Comparisons Challenge
Read each ACT-style question carefully, identify the comparison flaw, and choose the correct answer!
Frequently Asked Questions
❓ Why does the ACT test logical comparisons so frequently?
The ACT English section evaluates whether students can identify ambiguity and faulty logic that slips into everyday speech. Because idioms like "Her car is faster than John" sound acceptable to untrained ears, test-makers use comparison problems to measure analytical precision.
❓ How do I distinguish between "that of" and "those of"?
Identify the first noun being compared. If that noun is singular (e.g., the population of Tokyo), use that of (e.g., that of New York). If that noun is plural (e.g., the paintings in the Louvre), use those of (e.g., those of the Prado).
❓ Can a possessive apostrophe alone fix an illogical comparison?
Yes! Adding an apostrophe-s ('s) implicitly carries over the head noun. For example, "Sarah's scores arrived sooner than Jesse's" is 100% grammatically logical because Jesse's means Jesse's scores.
❓ What is the "other / else" rule in comparisons?
When comparing an individual or object to members of its own category, you must use other or else. Without it, you create an impossible paradox: "The cheetah runs faster than any animal" implies the cheetah runs faster than itself! Write: "faster than any other animal."
🔗 Continue Building ACT & SAT Grammar Mastery on ELA Free
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Conclusion
Logical comparisons may appear deceptively simple, but they are among the most dependable scoring opportunities on the ACT English Test. By training your eyes to identify what is truly being compared—and insisting that traits, actions, and entities match up with mathematical precision—you will turn tricky test questions into automatic points.
Continue practicing with our interactive problem sets, review our companion grammar masterclasses, and make visiting ELA Free your daily habit for fluent English communication and standardized test success!