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Usage and Mechanics

Grammar, punctuation, and sentence structure for ACT English

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📂 Subtopics in Usage and Mechanics

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1

Grammar & Usage

Agreement, pronouns, verb tense, sentence structure, modifiers and commonly confused words.

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2

Punctuation

Commas, semicolons, colons, apostrophes, dashes and end punctuation.

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Usage and Mechanics (ACT English)

Grammar and Usage

Subject-Verb Agreement

Rule: Singular subjects use singular verbs, plural use plural.

❌ "The box of cookies are here" ✓ "The box of cookies is here" (subject is "box")

Pronoun-Antecedent Agreement

Rule: Pronouns must match their antecedent in number.

❌ "Each student must bring their book" ✓ "Each student must bring his or her book" ✓ "Students must bring their books"

Punctuation

Commas

Use for:

  • Lists: "apples, oranges, and bananas"
  • Before FANBOYS with two complete sentences: "I ran, and she walked"
  • After introductory phrases: "After the game**,** we left"

Semicolons

Use to join two independent clauses: "I love reading**;** she prefers movies"

Sentence Structure

Run-on Sentences

❌ "I studied I passed" → needs punctuation/conjunction ✓ "I studied, and I passed" ✓ "I studied; I passed" ✓ "I studied. I passed"

Fragments

❌ "Because I was tired." → incomplete thought ✓ "I left early because I was tired."

ACT Tips

  • "No change" is often right! Don't overthink
  • Shorter is usually better (if grammatically correct)
  • Trust your ear but verify with rules

📚 Practice Problems

1Problem 1easy

❓ Question:

Which is correct?

A) Each of the students have a book. B) Each of the students has a book.

💡 Show Solution

Solution:

"Each" is the subject (singular). "Of the students" is a prepositional phrase.

Singular subject needs singular verb: has

Answer: B - Each of the students has a book.

ACT Tip: Ignore words between subject and verb when checking agreement!

2Problem 2easy

❓ Question:

Which is correct?

A) Each of the students have a book. B) Each of the students has a book.

💡 Show Solution

Solution:

"Each" is the subject (singular). "Of the students" is a prepositional phrase.

Singular subject needs singular verb: has

Answer: B - Each of the students has a book.

ACT Tip: Ignore words between subject and verb when checking agreement!

3Problem 3medium

❓ Question:

Which is correct?

A) I enjoy reading, my sister likes sports. B) I enjoy reading; my sister likes sports. C) I enjoy reading my sister likes sports.

💡 Show Solution

Solution:

Two independent clauses (complete sentences):

  • "I enjoy reading"
  • "My sister likes sports"

Cannot use:

  • C: No punctuation (run-on)
  • A: Comma alone (comma splice)

Must use:

  • Semicolon, period, or comma + conjunction

Answer: B - I enjoy reading; my sister likes sports.

4Problem 4medium

❓ Question:

Which is correct?

A) I enjoy reading, my sister likes sports. B) I enjoy reading; my sister likes sports. C) I enjoy reading my sister likes sports.

💡 Show Solution

Solution:

Two independent clauses (complete sentences):

  • "I enjoy reading"
  • "My sister likes sports"

Cannot use:

  • C: No punctuation (run-on)
  • A: Comma alone (comma splice)

Must use:

  • Semicolon, period, or comma + conjunction

Answer: B - I enjoy reading; my sister likes sports.

5Problem 5hard

❓ Question:

Which is the BEST revision?

Original: "The team, which practiced every day, they won the championship."

A) NO CHANGE B) The team, which practiced every day, won the championship. C) The team which practiced every day, they won the championship.

💡 Show Solution

Solution:

The original has two subjects: "team" AND "they"

This creates awkward redundancy.

Fix: Remove "they"

A: Keeps the error B: Removes "they" ✓ C: Missing commas around non-essential clause AND keeps "they"

Answer: B

ACT Tip: Avoid redundant subjects!

6Problem 6hard

❓ Question:

Which is the BEST revision?

Original: "The team, which practiced every day, they won the championship."

A) NO CHANGE B) The team, which practiced every day, won the championship. C) The team which practiced every day, they won the championship.

💡 Show Solution

Solution:

The original has two subjects: "team" AND "they"

This creates awkward redundancy.

Fix: Remove "they"

A: Keeps the error B: Removes "they" ✓ C: Missing commas around non-essential clause AND keeps "they"

Answer: B

ACT Tip: Avoid redundant subjects!

Explain using:
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📌 Related Topics in ACT English

ACT Rhetorical SkillsGrammar & UsagePunctuationRhetorical SkillsEnglish Section Strategy

❓ Frequently Asked Questions

What is Usage and Mechanics?▾
Grammar, punctuation, and sentence structure for ACT English
How can I study Usage and Mechanics effectively?▾
Start by reading the study notes and working through the examples on this page. Then use the flashcards to test your recall. Practice with the 6 problems provided, checking solutions as you go. Regular review and active practice are key to retention.
Is this Usage and Mechanics study guide free?▾
Yes — all study notes, flashcards, and practice problems for Usage and Mechanics on Study Mondo are free to access. No account is needed.
What course covers Usage and Mechanics?▾
Usage and Mechanics is part of the ACT Prep course on Study Mondo, specifically in the ACT English section. You can explore the full course for more related topics and practice resources.
Are there practice problems for Usage and Mechanics?▾
Yes, this page includes 6 practice problems with detailed solutions. Each problem includes a step-by-step explanation to help you understand the approach.