3.3 Modifiers, Comparisons, and Parallelism
Key Takeaways
- Opening modifiers should logically describe the noun that follows them; otherwise the sentence creates a dangling or misplaced modifier.
- Comparison questions require like-with-like logic, complete comparison terms, and the correct comparative or superlative form.
- Parallelism means matching grammatical forms in lists, pairs, and repeated structures so the reader can process the sentence cleanly.
- The best ACT English answer preserves the intended meaning while fixing the structure; a shorter answer is not enough if it creates a modifier, comparison, or parallelism error.
Why Structure Questions Feel Tricky
ACT English often tests sentence structure through small changes in word order. The sentence may sound nearly right, but one phrase points to the wrong noun, one comparison pairs unlike things, or one list item breaks the grammar pattern. These questions reward visual editing: mark the phrase, find what it attaches to, and check whether the sentence's pieces are balanced.
This section sits within Conventions of Standard English because it concerns usage and sentence formation. It also overlaps with Knowledge of Language because clear structure improves precision and style. On test day, treat these questions as meaning questions first and rule questions second. A structure is correct only if it says what the writer intends.
Modifiers
A modifier describes another word or group of words. Adjectives modify nouns. Adverbs modify verbs, adjectives, or other adverbs. Phrases and clauses can also act as modifiers. The ACT's favorite modifier errors are dangling modifiers and misplaced modifiers.
A dangling modifier appears when the sentence does not name the thing being modified or places the wrong noun after the opening phrase. Example: Walking through the archive, the rare map caught Elena's attention. The map was not walking through the archive; Elena was. A correct revision names the actor after the modifier: Walking through the archive, Elena noticed the rare map.
A misplaced modifier is present but attached to the wrong word. "The artist displayed a sculpture in the gallery made of glass" could imply the gallery was made of glass. Move the modifier next to the noun it describes: The artist displayed a glass sculpture in the gallery.
Use this table when a phrase feels slippery:
| Structure | Question to ask | Better revision habit |
|---|---|---|
| Opening -ing phrase | Who is doing this action? | Put that noun immediately after the comma |
| Opening participle phrase | What noun is being described? | Start the main clause with that noun |
| Only, almost, nearly, just | What word should be limited? | Place the modifier next to that word |
| Which or who clause | What noun does the clause describe? | Put the clause immediately after that noun |
| Adjective/adverb choice | Is a noun or action being described? | Use adjective for nouns, adverb for verbs or adjectives |
Placement Words
Small modifiers such as only, almost, nearly, and just can change meaning dramatically. "The guide only photographed the entrance" means the guide photographed but did nothing else. "The guide photographed only the entrance" means the entrance was the only subject photographed. ACT English usually prefers the placement that matches the passage's intended meaning.
Comparisons
A comparison must compare like things. A person should be compared with another person, a painting with another painting, and a feature with another feature. Faulty comparisons often hide behind phrases such as more than, less than, unlike, as...as, better than, and the most.
Incorrect: The pacing of the documentary is faster than the original film. The sentence compares pacing to film. Correct: The pacing of the documentary is faster than that of the original film. Now pacing is compared with pacing.
Use comparative forms for two things: clearer, more precise, less expensive. Use superlative forms for three or more: clearest, most precise, least expensive. If a sentence compares two proposals, better is usually right; if it chooses among five proposals, best is usually right.
Complete the comparison when the missing term creates confusion. "The new edition is more detailed" may be fine if the previous sentence names the older edition. But if no comparison object is clear, ACT English may prefer "more detailed than the 2018 edition."
Parallelism
Parallel structure means matching grammar in a list or paired construction. Parallelism makes sentences efficient because readers can process each item in the same form. ACT English tests lists of nouns, verbs, infinitives, gerunds, clauses, and phrases.
Incorrect: The internship teaches students to collect data, analyzing results, and how reports are written. The list mixes an infinitive, a gerund phrase, and a noun clause. Correct: The internship teaches students to collect data, analyze results, and write reports.
Parallelism also appears in paired phrases:
- both accurate and concise
- either revise the chart or delete the chart
- not only mapped the trail but also photographed the markers
- between collecting the data and publishing the findings
The words after each half of the pair should match. Do not pair a noun with a full clause unless the meaning requires it.
Exam-Day Workflow
- If the sentence opens with a descriptive phrase, check the noun after the comma.
- If the sentence contains a comparison word, identify both sides of the comparison.
- If the sentence contains a list or pair, underline the repeated pattern.
- Choose the answer that fixes structure without adding wordiness or changing meaning.
- Read the final sentence for logic, not just grammar.
Common Traps
Modifier traps often use passive voice to hide the actor: "After reviewing the notes, the conclusion was revised." The conclusion did not review the notes. A clearer answer names the reviewer. Comparison traps often compare a noun to a possessive form incorrectly: "Maria's essay is clearer than James" compares an essay to a person. The fix is James's essay or that of James, depending on style.
Parallelism traps often include one tempting choice that is shorter but breaks the pattern. For example, "The plan calls for surveying residents, to update signs, and the repair of sidewalks" needs a consistent set: surveying residents, updating signs, and repairing sidewalks. The matched version is easier to read and more defensible under ACT timing.
The goal is not to make sentences fancy. It is to make every phrase point to the right target and every repeated structure carry the same grammatical weight.
Which revision fixes the dangling modifier? "Walking through the archive, the rare map caught Elena's attention."
Which choice makes the comparison logical? "The pacing of the documentary is faster than ___ the original film."
Which revision is parallel? "The internship teaches students to collect data, analyzing results, and how reports are written."