Grammar in writing

Overview

Grammar in writing is a critical component of the ACT English Test, representing approximately 50-55% of all questions students encounter. Unlike traditional grammar instruction that focuses on memorization of rules in isolation, ACT grammar in writing tests a student's ability to recognize and correct errors within the context of complete passages. The ACT English Test presents four prose passages, each accompanied by 15 questions that assess grammar, punctuation, sentence structure, and rhetorical skills. Understanding how grammar functions within authentic writing contexts—rather than in isolated sentences—is what distinguishes high-scoring students from those who struggle.

The ACT approaches grammar testing through an editing lens, asking students to identify the best version of underlined portions within passages. This format mirrors real-world writing and revision processes, where writers must evaluate multiple options and select the most effective, grammatically correct choice. Questions range from straightforward error identification (such as subject-verb agreement violations) to more nuanced decisions about sentence construction, modifier placement, and parallel structure. The test rewards students who can quickly recognize patterns, apply grammatical principles accurately, and distinguish between technically correct options based on clarity and style.

Within the broader Writing curriculum, grammar serves as the foundation upon which effective essay organization and style are built. While rhetorical skills questions focus on organization, transitions, and purpose, grammar questions ensure that the mechanical execution of ideas meets standard written English conventions. Mastery of grammar in writing directly impacts a student's ability to score in the upper ranges (28-36) on the ACT English Test, as these questions are distributed throughout every passage and cannot be avoided or compensated for through other skills alone.

Learning Objectives

• [ ] Identify when Grammar in writing is being tested on the ACT English Test
• [ ] Explain the core rule or strategy behind Grammar in writing concepts
• [ ] Apply Grammar in writing to ACT-style questions accurately
• [ ] Distinguish between grammar questions and rhetorical skills questions within passages
• [ ] Evaluate multiple grammatically correct options to select the most effective choice
• [ ] Recognize common error patterns that appear repeatedly across ACT passages
• [ ] Execute a systematic approach to grammar questions that maximizes accuracy and efficiency

Prerequisites

• Basic parts of speech identification: Understanding nouns, verbs, adjectives, adverbs, pronouns, prepositions, and conjunctions is essential because ACT grammar questions require recognizing how words function within sentences.
• Sentence structure fundamentals: Knowledge of independent clauses, dependent clauses, phrases, and basic sentence patterns enables students to identify structural errors and punctuation issues.
• Standard punctuation conventions: Familiarity with comma, semicolon, colon, apostrophe, and dash usage provides the baseline for recognizing punctuation errors in context.
• Subject-verb relationship: The ability to identify subjects and their corresponding verbs is crucial for detecting agreement errors, which appear frequently on the ACT.

Why This Topic Matters

Grammar in writing represents the most heavily weighted category on the ACT English Test, making it impossible to achieve a competitive score without mastery. Approximately 40 of the 75 English questions directly test grammar and usage conventions, with an additional 12-15 questions testing sentence structure and formation. This means that grammar-focused questions constitute roughly 70% of the English Test score. Students who master grammar in writing typically see score improvements of 4-6 points on the English section, which translates to 1-2 points on the composite ACT score.

In real-world applications, the grammar skills tested on the ACT directly transfer to college writing, professional communication, and critical reading. The ability to recognize and correct grammatical errors improves a student's own writing quality, enhances editing capabilities, and develops the linguistic awareness necessary for effective communication across academic disciplines. Employers and college professors consistently rank clear, grammatically correct writing among the most valued skills in graduates.

On the ACT, grammar in writing appears in predictable patterns across four prose passages covering topics in social studies, natural sciences, humanities, and literary narrative. Questions are embedded within the passages, with underlined portions followed by four answer choices (including "NO CHANGE"). Common question formats include: identifying subject-verb agreement errors, correcting pronoun-antecedent problems, fixing modifier placement issues, selecting appropriate verb tenses, ensuring parallel structure, correcting punctuation errors, and eliminating wordiness or redundancy. The test deliberately includes distractors that sound correct in casual speech but violate standard written English conventions, making it essential to apply formal grammar rules rather than relying on what "sounds right."

Core Concepts

Subject-Verb Agreement

Subject-verb agreement requires that singular subjects pair with singular verbs and plural subjects pair with plural verbs. On the ACT, this concept is tested through sentences where the subject and verb are separated by prepositional phrases, relative clauses, or other intervening elements designed to obscure the true subject. The key strategy involves identifying the core subject by eliminating modifying phrases and ensuring the verb matches the subject's number.

Common ACT patterns include:

• Prepositional phrase separation: "The collection of stamps is valuable" (not "are")
• Compound subjects joined by "and": "The teacher and the student are present" (plural verb)
• Compound subjects joined by "or/nor": The verb agrees with the nearest subject
• Indefinite pronouns: Some are always singular (everyone, each, either), some always plural (both, few, many), and some depend on context (all, some, none)

Pronoun-Antecedent Agreement

Pronouns must agree with their antecedents in number, gender, and person. The ACT frequently tests this concept by placing pronouns far from their antecedents or by using ambiguous pronoun references. Students must identify what noun the pronoun replaces and ensure consistency.

Critical rules include:

1. Singular antecedents require singular pronouns: "Each student must bring his or her book" (not "their")
2. Plural antecedents require plural pronouns: "The students must bring their books"
3. Collective nouns treated as units take singular pronouns: "The committee announced its decision"
4. Pronouns must have clear, unambiguous antecedents: Avoid situations where "it" or "they" could refer to multiple nouns

Verb Tense Consistency and Formation

Verb tense indicates when an action occurs, and the ACT tests whether students can maintain consistent tense throughout a passage and select the appropriate tense for the context. The test also assesses knowledge of irregular verb forms and proper formation of perfect and progressive tenses.

Key principles:

• Maintain consistent tense unless the timeline genuinely shifts
• Use present perfect (has/have + past participle) for actions beginning in the past and continuing to the present
• Use past perfect (had + past participle) for actions completed before another past action
• Recognize irregular verb forms: go/went/gone, see/saw/seen, lie/lay/lain vs. lay/laid/laid

Modifier Placement

Modifiers (adjectives, adverbs, phrases, and clauses that describe other words) must be placed immediately adjacent to the words they modify. Misplaced modifiers create confusion or unintended meanings, while dangling modifiers lack a clear word to modify.

ACT patterns:

• Opening modifiers must be followed immediately by the word they describe: "Running quickly, the student arrived on time" (not "the bell rang")
• Limiting modifiers (only, almost, nearly, just) should be placed directly before the word they modify
• Relative clauses (who, which, that) should follow the noun they describe

Parallel Structure

Parallel structure requires that items in a series, comparisons, or paired constructions use the same grammatical form. This concept appears frequently in ACT questions testing lists, correlative conjunctions (either/or, neither/nor, not only/but also), and comparisons.

Examples of parallelism:

• List: "She enjoys reading, writing, and hiking" (not "to hike")
• Comparison: "The new policy is more effective than the old one" (not "the old policy was")
• Correlative conjunctions: "Either study now or study later" (matching verb forms)

Punctuation in Context

The ACT tests punctuation as a tool for clarifying meaning and establishing relationships between sentence elements. Key punctuation concepts include:

Comma usage:

• Separating independent clauses with coordinating conjunctions (FANBOYS)
• Setting off introductory elements
• Separating items in a series
• Setting off nonessential clauses and phrases
• Avoiding comma splices (joining independent clauses with only a comma)

Semicolon usage:

• Joining closely related independent clauses
• Separating complex items in a series

Colon usage:

• Introducing lists, explanations, or elaborations after independent clauses

Apostrophe usage:

• Indicating possession (singular: student's; plural: students')
• Forming contractions (it's = it is; its = possessive)

Sentence Fragments and Run-ons

Sentence fragments lack either a subject, a verb, or a complete thought, while run-on sentences improperly join independent clauses. The ACT tests these concepts by presenting options that create or correct these errors.

Fragment types:

• Dependent clause alone: "Because the weather was cold."
• Missing subject or verb: "Running through the park."
• Incomplete thought: "The reason being."

Run-on types:

• Fused sentence: Two independent clauses with no punctuation
• Comma splice: Two independent clauses joined only by a comma

Wordiness and Redundancy

The ACT values concise, clear expression. Questions testing this concept present options with varying levels of wordiness, and the correct answer eliminates unnecessary words while preserving meaning.

Common redundancies to eliminate:

• "Past history" (history is always past)
• "Advance planning" (planning is inherently advance)
• "Completely eliminate" (eliminate means completely remove)
• "Each and every" (choose one)

Concept Relationships

The grammar concepts tested on the ACT form an interconnected system where mastery of one area supports understanding of others. Subject-verb agreement and pronoun-antecedent agreement both rely on the fundamental skill of identifying subjects and understanding number (singular vs. plural). These agreement concepts connect directly to sentence structure, as students must parse complex sentences to locate the true subject or antecedent among modifying phrases and clauses.

Verb tense consistency relates to sentence structure and punctuation because understanding how clauses connect (through coordination or subordination) helps determine appropriate tense relationships. For example, recognizing that a dependent clause beginning with "after" or "before" signals a time relationship guides verb tense selection in both clauses.

Modifier placement connects to sentence structure and punctuation because correctly positioning modifiers often requires understanding where phrases and clauses begin and end, which punctuation marks help clarify. A misplaced modifier often results from incorrect punctuation that separates the modifier from its intended target.

Parallel structure integrates with sentence structure and punctuation because creating parallel constructions requires recognizing grammatical patterns and using punctuation (particularly commas and semicolons) to separate parallel elements clearly.

The relationship map flows as follows:

Sentence Structure Recognition → enables → Subject Identification → enables → Subject-Verb Agreement and Pronoun-Antecedent Agreement

Clause Relationships → informs → Verb Tense Selection and Punctuation Choices

Phrase and Clause Boundaries → determines → Modifier Placement and Parallel Structure

All concepts converge on the ultimate goal: Clear, Concise, Grammatically Correct Expression

High-Yield Facts

⭐ Subject-verb agreement errors most commonly occur when prepositional phrases separate the subject from the verb—eliminate the phrase to identify the true subject.

⭐ Indefinite pronouns like "everyone," "each," "either," and "neither" are always singular and require singular verbs and pronouns.

⭐ Comma splices (joining two independent clauses with only a comma) are always incorrect on the ACT—use a semicolon, period, or comma with coordinating conjunction instead.

⭐ Opening modifiers must be immediately followed by the word they modify—if a comma follows the modifier, the next word must be what the modifier describes.

⭐ "Its" is possessive while "it's" means "it is"—the ACT frequently tests this distinction in context.

• Collective nouns (team, committee, family) typically take singular verbs when acting as a unit and plural verbs when emphasizing individual members.

• The past participle form of irregular verbs (gone, seen, done) requires a helping verb (has, have, had) and cannot stand alone.

• Semicolons can only join independent clauses or separate complex items in a series—they cannot introduce lists or follow dependent clauses.

• Pronouns must have clear, unambiguous antecedents—if "it," "they," or "this" could refer to multiple nouns, the pronoun reference is faulty.

• Items in a list or series must maintain parallel grammatical structure—mixing verb forms (running, to swim, biking) is incorrect.

• Apostrophes show possession or form contractions but never make words plural—"apple's" means belonging to the apple, while "apples" is simply plural.

• The word "being" is almost always incorrect on the ACT—it creates wordiness and awkward constructions.

• When "or" or "nor" joins compound subjects, the verb agrees with the nearest subject.

• Relative pronouns "who" and "whom" refer to people, "which" refers to things, and "that" can refer to either but is preferred for essential clauses.

• Adverbs modify verbs, adjectives, and other adverbs, while adjectives modify only nouns and pronouns—confusing these creates modification errors.

Common Misconceptions

Misconception: Subject-verb agreement is determined by the noun closest to the verb.

Correction: The verb must agree with the actual subject of the sentence, not necessarily the nearest noun. Prepositional phrases and other modifiers between the subject and verb do not affect agreement. In "The box of chocolates is on the table," the singular subject "box" determines the verb, not the plural "chocolates."

Misconception: Pronouns should agree with what sounds natural in casual speech.

Correction: The ACT tests formal written English, which differs from conversational usage. While "Everyone brought their lunch" is increasingly accepted in speech, the ACT requires "Everyone brought his or her lunch" because "everyone" is grammatically singular. Always apply formal grammar rules, not conversational patterns.

Misconception: Longer, more complex answer choices are more sophisticated and therefore correct.

Correction: The ACT consistently rewards concise, clear expression. When multiple answer choices are grammatically correct, the shortest option that preserves the original meaning is typically correct. Wordiness and redundancy are errors, not signs of sophistication.

Misconception: Commas can be placed wherever a speaker would pause.

Correction: Comma placement follows specific grammatical rules, not speech patterns. While pauses sometimes align with comma placement, many grammatically required commas occur where speakers don't pause, and many natural pauses don't require commas. Master the specific rules for comma usage rather than relying on intuition.

Misconception: "Who" and "whom" are interchangeable, or "whom" is always more formal and correct.

Correction: "Who" functions as a subject (who performed the action), while "whom" functions as an object (received the action). Use "who" when it could be replaced by "he/she" and "whom" when it could be replaced by "him/her." The choice depends on grammatical function, not formality level.

Misconception: Semicolons and colons are interchangeable ways to introduce lists or explanations.

Correction: Colons introduce lists, explanations, or elaborations after independent clauses. Semicolons join two independent clauses or separate complex items in a series. Using a semicolon to introduce a list is incorrect. The sentence before a colon must be able to stand alone; the sentence before a semicolon must also be independent, and what follows must be independent as well.

Misconception: Passive voice is always incorrect or inferior to active voice.

Correction: While the ACT generally prefers active voice for clarity and conciseness, passive voice is grammatically correct and sometimes necessary when the actor is unknown or when emphasizing the recipient of the action. The test penalizes passive voice only when it creates wordiness or awkwardness, not simply for being passive.

Worked Examples

Example 1: Subject-Verb Agreement with Intervening Phrases

Passage excerpt: "The collection of rare books, including several first editions and manuscripts from the 18th century, were donated to the university library."

Question:

A. NO CHANGE

B. was

C. are

D. have been

Step 1: Identify the subject by eliminating modifying phrases.

Remove "of rare books" (prepositional phrase) and "including several first editions and manuscripts from the 18th century" (participial phrase). The core sentence becomes: "The collection were donated."

Step 2: Determine if the subject is singular or plural.

"Collection" is a singular noun. Even though it refers to multiple books, the word "collection" itself is singular.

Step 3: Select the verb that agrees with the singular subject.

A singular subject requires a singular verb. "Were" (plural) is incorrect. "Was" (singular) is correct.

Step 4: Evaluate remaining options.

• Option A (NO CHANGE): "were" is plural—incorrect
• Option B: "was" is singular—matches the singular subject "collection"
• Option C: "are" is plural present tense—incorrect for both number and tense
• Option D: "have been" is plural perfect tense—incorrect

Answer: B. The correct sentence reads: "The collection of rare books, including several first editions and manuscripts from the 18th century, was donated to the university library."

Connection to learning objectives: This example demonstrates how to identify when grammar is being tested (subject-verb agreement), explains the core rule (verbs must agree with their subjects in number), and applies the strategy (eliminate intervening phrases to find the true subject) to an ACT-style question.

Example 2: Modifier Placement and Sentence Structure

Passage excerpt: "Hoping to improve her test scores, the study guide was used by Maria every evening."

Question:

A. NO CHANGE

B. Maria used the study guide every evening

C. every evening the study guide was used by Maria

D. the study guide, which was used by Maria every evening,

Step 1: Identify the opening modifier and what it describes.

"Hoping to improve her test scores" is a participial phrase that must describe the person doing the hoping—Maria, not the study guide.

Step 2: Check what word immediately follows the modifier.

In the original sentence, "the study guide" follows the comma after the modifier. This creates a dangling modifier because the study guide cannot hope to improve test scores.

Step 3: Evaluate each option for correct modifier placement.

• Option A: "the study guide" follows the modifier—dangling modifier error
• Option B: "Maria" follows the modifier—correctly places the person hoping immediately after the modifier
• Option C: "the study guide" still follows the modifier (after "every evening")—dangling modifier remains
• Option D: "the study guide" follows the modifier—dangling modifier error

Step 4: Verify the correct option creates a clear, grammatically correct sentence.

Option B: "Hoping to improve her test scores, Maria used the study guide every evening." The modifier correctly describes Maria, who immediately follows it.

Answer: B. This option corrects the dangling modifier by placing Maria (the person hoping) immediately after the introductory phrase, and it uses active voice for clarity and conciseness.

Connection to learning objectives: This example shows how to identify modifier placement errors, explains the rule that opening modifiers must be followed by the word they describe, and demonstrates applying this principle to select the correct answer while eliminating options that maintain the error or create new problems.

Exam Strategy

When approaching grammar questions on the ACT English Test, implement a systematic process that maximizes accuracy while managing time efficiently. The average student has approximately 45 seconds per question, making strategic approaches essential.

Step 1: Read the sentence containing the underlined portion plus the sentence before and after it. Context is crucial for determining verb tense, pronoun references, and logical connections. Never evaluate the underlined portion in isolation.

Step 2: Identify what grammatical concept is being tested. Look for trigger patterns:

• Underlined verbs → check subject-verb agreement and tense consistency
• Underlined pronouns → check pronoun-antecedent agreement and clarity
• Underlined punctuation → check whether clauses are independent or dependent
• Underlined phrases at sentence beginnings → check modifier placement
• Underlined lists or comparisons → check parallel structure

Step 3: Eliminate obviously incorrect answers first. Often, two answer choices contain clear errors (wrong verb form, comma splice, dangling modifier), allowing you to focus on distinguishing between two remaining options.

Step 4: When multiple options are grammatically correct, choose the most concise option that preserves meaning. The ACT rewards clarity and brevity. If Options B and C are both grammatically correct but B is shorter, select B unless it changes the intended meaning.

Step 5: Trust grammar rules over what "sounds right." Many incorrect options sound acceptable in casual speech but violate formal written English conventions. If you've identified a specific rule violation, select the answer that corrects it even if it sounds less familiar.

Trigger words and phrases to watch for:

• "Being" → almost always signals wordiness; look for a more concise option
• "Would have" in if-clauses → incorrect; should be "had"
• "Between you and I" → incorrect; should be "between you and me" (object form)
• "Reason is because" → redundant; use "reason is that"
• "Could of," "should of" → incorrect; should be "could have," "should have"

Time allocation advice:

• Spend no more than 30-45 seconds on straightforward grammar questions
• Allocate up to 60 seconds for complex questions involving multiple concepts
• If you're uncertain after 60 seconds, make your best guess and mark the question for review if time permits
• Grammar questions are typically faster to answer than rhetorical skills questions, so use them to bank time for more complex passage-level questions

Memory Techniques

FANBOYS - Coordinating conjunctions that can join independent clauses with a comma:

For, And, Nor, But, Or, Yet, So

AAAWWUBBIS - Common subordinating conjunctions that create dependent clauses:

After, Although, As, When, While, Where, Until, Because, Before, If, Since

The "It's/Its" Test: If you can replace the word with "it is" or "it has," use "it's" (contraction). If not, use "its" (possessive). Example: "The dog wagged its tail" (cannot say "it is tail").

The "Who/Whom" Trick: Rephrase the sentence with "he/him." If "him" fits, use "whom." If "he" fits, use "who."

• "Give the book to who/whom?" → "Give the book to him" → Use "whom"
• "Who/whom is calling?" → "He is calling" → Use "who"

Singular Indefinite Pronoun Memory Device: "Each Either Neither One" - These words all contain the letter "e" and are all singular. Add to this list: everyone, everybody, everything, someone, somebody, something, anyone, anybody, anything, no one, nobody, nothing.

Comma Before Coordinating Conjunction Visualization: Picture two complete sentences (independent clauses) as two separate houses. A coordinating conjunction (FANBOYS) is a bridge connecting them. The comma is the foundation of the bridge on the first house's side. You need both the comma (foundation) and the conjunction (bridge) to connect the houses properly.

Parallel Structure Pattern Recognition: When you see a list or comparison, write down the grammatical form of the first item. Every subsequent item must match that form exactly:

• First item: verb + -ing → All items must be verb + -ing
• First item: to + verb → All items must be to + verb
• First item: noun → All items must be nouns

Summary

Grammar in writing on the ACT English Test assesses a student's ability to recognize and correct errors within authentic prose passages, testing subject-verb agreement, pronoun-antecedent agreement, verb tense consistency, modifier placement, parallel structure, punctuation, sentence structure, and concise expression. Success requires mastering specific grammatical rules, identifying error patterns quickly, and applying systematic strategies to evaluate answer choices. The test rewards students who can distinguish between formal written English and casual speech patterns, eliminate wordiness while preserving meaning, and recognize that the shortest grammatically correct option is typically correct. With approximately 40 of 75 questions directly testing grammar concepts, this topic represents the highest-yield area for score improvement on the ACT English Test. Students must develop the ability to parse complex sentences to identify true subjects and antecedents, understand how punctuation clarifies relationships between clauses, and ensure that modifiers are positioned adjacent to the words they describe. Mastery of these concepts, combined with efficient time management and strategic elimination of incorrect answers, enables students to achieve scores in the upper ranges of the ACT English Test.

Key Takeaways

• Grammar questions constitute approximately 50-55% of the ACT English Test, making them the highest-yield category for score improvement
• Subject-verb agreement errors most commonly occur when prepositional phrases or other modifiers separate the subject from the verb—eliminate intervening words to identify the true subject
• Opening modifiers must be immediately followed by the word they modify; if not, a dangling modifier error exists
• When multiple answer choices are grammatically correct, select the most concise option that preserves the original meaning
• Comma splices (joining independent clauses with only a comma) are always incorrect; use semicolons, periods, or commas with coordinating conjunctions instead
• Trust formal grammar rules over conversational patterns—the ACT tests standard written English, which differs from casual speech
• Implement a systematic approach: read surrounding context, identify the concept being tested, eliminate obvious errors, and choose the clearest, most concise correct option

Related Topics

Rhetorical Skills and Strategy: While grammar focuses on mechanical correctness, rhetorical skills questions test organization, transitions, and purpose. Mastering grammar provides the foundation for addressing these higher-level questions about passage effectiveness and author's intent.

Sentence Structure and Formation: This closely related topic examines how clauses combine to create different sentence types (simple, compound, complex, compound-complex) and how to avoid fragments and run-ons. Grammar mastery enables more sophisticated analysis of sentence construction.

Punctuation in Context: Though covered within grammar, punctuation deserves deeper study as it relates to clause relationships, parenthetical elements, and clarity. Understanding punctuation rules enhances both grammar accuracy and rhetorical effectiveness.

Writing Process and Revision: The editing skills developed through ACT grammar practice directly transfer to revising one's own writing. Students who master grammar recognition can more effectively edit their ACT essays and college application materials.

Reading Comprehension: Strong grammar knowledge improves reading comprehension by helping students parse complex sentences, understand relationships between clauses, and recognize how authors use sentence structure for emphasis and clarity.

Practice CTA

Now that you've mastered the core concepts of grammar in writing for the ACT, it's time to apply these strategies to practice questions. The flashcards will help you memorize high-yield rules and common error patterns, while the practice questions will develop your ability to identify and correct errors under timed conditions. Remember that grammar mastery comes through repeated exposure to question patterns and consistent application of the systematic approach outlined in this guide. Each practice question you complete strengthens your pattern recognition and increases your speed, moving you closer to your target score. Approach practice with confidence—you now have the knowledge and strategies needed to tackle any grammar question the ACT presents!