Punctuation

✏️ Commas

Part 1 of 7 — Items in a Series, Introductory Elements, Nonessential Clauses & Coordinate Adjectives

Commas are the most frequently tested punctuation mark on the ACT English section (50 questions in 35 minutes on the enhanced ACT, each with 4 answer choices). Comma questions show up in nearly every passage, so mastering these rules gives you a significant scoring advantage.

The Four Big Comma Rules on the ACT:

Why this matters: The ACT doesn't just test whether you know the rules — it tests whether you can avoid adding commas where they don't belong.

Items in a Series & the Oxford Comma

When you list three or more items, place commas between each item. The ACT typically includes the comma before the conjunction (the Oxford comma).

Correct:

• ✅ The lab requires goggles, gloves, and a lab coat.
• ✅ She studied biology, chemistry, and physics.

Incorrect — Missing Comma:

• ❌ The lab requires goggles, gloves and a lab coat.

Two-Item Lists — No Comma Before "and":

• ✅ She studied biology and chemistry.
• ❌ She studied biology, and chemistry. (Don't add a comma with only two items!)

ACT Trap: The ACT will sometimes offer an answer that inserts a comma between just two items. Always count the items in the list before choosing.

Introductory Elements:

After an introductory word, phrase, or clause, use a comma:

• ✅ However, the results were inconclusive. (At the start of a sentence, "however" takes just a comma after it.)
• ✅ After running for three miles, she stopped to rest.
• ✅ When the bell rang, students rushed to the door.

Short introductory phrases (1–2 words) may sometimes omit the comma, but on the ACT, the safer choice is to include it.

Comma Usage — Spot the Correct Version 🔍

Nonessential (Nonrestrictive) Clauses

A nonessential clause adds extra information that can be removed without changing the sentence's meaning. Set it off with commas on both sides.

Nonessential (commas needed):

• ✅ My brother, who is a pilot, travels frequently.
• Removing "who is a pilot" leaves a complete sentence: My brother travels frequently.

Essential (no commas):

• ✅ Students who study regularly tend to score higher.
• Removing "who study regularly" changes the meaning — we no longer know which students.

The "Which" vs. "That" Shortcut:

• Which → usually nonessential → needs commas: The car, which was red, sped away.
• That → usually essential → no commas: The car that was red sped away.

Coordinate Adjectives:

Two adjectives are coordinate (equal) when you can swap their order or insert "and" between them:

• ✅ It was a cold, dreary morning. (You could say "dreary, cold morning" or "cold and dreary morning.")
• ❌ She wore a bright red scarf. ("Red bright scarf" sounds wrong — not coordinate, so no comma.)

ACT Tip: Try the swap test. If the adjectives sound natural in either order, use a comma.

Add the Missing Punctuation ✏️

Type "comma" or "none" for each sentence. When a sentence has two blanks, both blanks take the same mark.

1. "The museum ___ which was built in 1920 ___ is undergoing renovation." — What punctuation goes in each blank?

2. "Running through the park ___ she noticed a rare bird." — What punctuation goes in the blank?

3. "They brought sandwiches ___ drinks ___ and fruit to the picnic." — What punctuation goes in each blank?

Quick-Check: Comma Rules 🔍

ACT-Style Passage Practice 📋

🔗 Semicolons & Colons

Part 2 of 7 — Joining Independent Clauses, Introducing Lists & Semicolons vs. Commas

Semicolons and colons appear on nearly every ACT English section. They look intimidating, but the rules are straightforward once you learn them.

Key Principle: Both semicolons and colons must be preceded by a complete sentence (independent clause). If the words before the mark can't stand alone, the punctuation is wrong.

The Semicolon

Rule 1 — Join Two Independent Clauses: A semicolon replaces a period between two closely related sentences.

• ✅ The experiment failed; the researchers adjusted their method.
• ❌ The experiment failed; and the researchers adjusted their method. (Don't use a semicolon + FANBOYS together.)

Rule 2 — Semicolon with Conjunctive Adverbs (Between Two Clauses): When a word like however, therefore, moreover, consequently, furthermore sits between two independent clauses, place a semicolon before it and a comma after it:

• ✅ The data was inconclusive; however, the team continued.
• ❌ The data was inconclusive, however, the team continued. (This is a comma splice!)

But "however" doesn't always need a semicolon. When it interrupts a single clause, it is just an aside, so set it off with a pair of commas:

• ✅ The team, however, continued the study.
• ❌ The team; however, continued the study. ("The team" can't stand alone, so no semicolon.)

Test: Cover "however." If complete sentences remain on both sides, use semicolon + comma. If only one sentence remains, use a pair of commas.

Rule 3 — Semicolons in Complex Lists: Use semicolons to separate items in a list when the items themselves contain commas:

• ✅ The team traveled to Austin, Texas; Portland, Oregon; and Miami, Florida.

ACT Trap: The ACT will offer a semicolon between a dependent clause and an independent clause. Remember — both sides of a semicolon must be independent clauses.

• ❌ Although she studied hard; she didn't pass. ("Although she studied hard" is dependent.)

Semicolons — Right or Wrong? 🔍

The Colon

The One Colon Rule: The words before a colon must be a complete sentence. That's why a colon can never come right after a verb or a preposition — the sentence isn't finished yet.

Rule 1 — Introduce a List (After a Complete Sentence):

• ✅ The kit includes the following items: a wrench, pliers, and a screwdriver.
• ❌ The kit includes: a wrench, pliers, and a screwdriver. ("The kit includes" is not a complete sentence — the verb "includes" still needs its object, so the colon cuts the sentence off mid-thought. Fix it by deleting the colon or by adding "the following items" so a complete sentence comes first.)

Rule 2 — Introduce an Explanation or Elaboration:

• ✅ There was one problem: the bridge had collapsed.
• ✅ She had a simple philosophy: work hard, stay humble.

Rule 3 — No Colon Right After a Verb or Preposition: This is the same complete-sentence rule in action. A verb or preposition still needs its object, so the words before the colon aren't a complete sentence:

• ❌ She enjoys: reading, hiking, and swimming. (after the verb "enjoys")
• ✅ She enjoys reading, hiking, and swimming.
• ❌ The box was filled with: books, papers, and photos. (after the preposition "with")
• ✅ The box was filled with books, papers, and photos.

Colon vs. Semicolon Quick Test:

• Semicolon → both sides must be independent clauses
• Colon → left side must be an independent clause; right side can be a list, clause, or fragment

ACT Tip: If the part before the colon can stand alone as a sentence, the colon is probably correct. If it can't, it's wrong.

Choose the Correct Punctuation ✏️

Type "semicolon" or "colon" for each blank.

1. "The museum has an impressive collection ___ ancient sculptures, Renaissance paintings, and modern art." — The blank needs a …

2. "She finished her essay early ___ therefore, she had time to review it." — The blank needs a …

3. "He had one goal ___ to finish the marathon." — The blank needs a …

Quick-Check: Semicolons & Colons 🔍

ACT-Style Passage Practice 📋

🔤 Apostrophes

Part 3 of 7 — Possessives, Contractions, Its vs. It's & Plural Possessives

Apostrophe questions appear on virtually every ACT English section. They test two things: possession and contractions. The ACT's favorite trick is confusing possessive pronouns (which never use apostrophes) with contractions (which always do).

Two Jobs for Apostrophes:

Critical Rule: Possessive pronouns — its, their, your, whose — NEVER take apostrophes.

Possessives — Singular & Plural

Singular Possessive — Add 's:

• the student's essay (one student)
• the boss's office (one boss — yes, add 's even if the word ends in s)
• James's car (ACT follows the rule: always add 's for singular)

Plural Possessive — Add ' after the s:

• the students' essays (multiple students)
• the teachers' lounge (multiple teachers)

Irregular Plurals — Add 's:

• the children's toys (children is already plural)
• the women's team
• the people's choice

Quick Decision Tree:

1. Is the owner singular? → Add 's (the cat's toy)
2. Is the owner a regular plural (ends in s)? → Add ' (the cats' toys)
3. Is the owner an irregular plural? → Add 's (the children's toys)

ACT Trap: The ACT will offer a plural noun with an apostrophe when no possession is intended.

• ❌ The student's studied for hours. (No possession — just a plural: The students studied for hours.)

Apostrophes — Choose Correctly 🔍

Contractions & Commonly Confused Pairs

Common Contractions:

• it's = it is / it has
• they're = they are
• you're = you are
• who's = who is / who has
• there's = there is

Possessive Pronouns (NO Apostrophe):

• its → The dog wagged its tail.
• their → Their house is on the corner.
• your → Your grade improved.
• whose → Whose book is this?

The ACT's Big Three Confusion Pairs:

Strategy: Every time you see an apostrophe in a pronoun on the ACT, try expanding it. If "it is" or "they are" doesn't make sense, remove the apostrophe.

ACT Tip: Don't guess based on which form "looks" more formal — sometimes the contraction is correct (It's going to rain = It is going to rain). Expand every time: if "it is," "they are," or "you are" fits, keep the apostrophe; if it doesn't, use the possessive pronoun with no apostrophe.

It's vs. Its — Type the Correct Word ✏️

1. "The university announced ___ new admissions policy." — Type "its" or "it's."

2. "___ going to be a challenging semester." — Type "Its" or "It's."

3. "The cat cleaned ___ paws after dinner." — Type "its" or "it's."

Quick-Check: Apostrophe Rules 🔍

ACT-Style Passage Practice 📋

— Dashes & Parentheses

Part 4 of 7 — Em Dashes for Emphasis, Parenthetical Asides & When to Use Which

Dashes and parentheses both set off extra information in a sentence, but they create different effects. The ACT tests whether you know the rules for each — and whether you can keep them consistent.

The Big Three Tools for Setting Off Information:

Critical ACT Rule: When you use two dashes or two commas or two parentheses to set off information, you must use the same mark on both sides. You cannot mix them.

• ❌ The results — which surprised everyone, were published Friday.
• ✅ The results — which surprised everyone — were published Friday.

Em Dashes

Use 1 — Set Off a Dramatic or Emphatic Aside:

• The discovery — one that would change the field forever — was published in a small journal.
• The dashes emphasize the importance of the clause.

Use 2 — Introduce an Explanation or List (Like a Colon):

• She had one priority — finishing the project on time.
• Three states — California, Texas, and Florida — have the largest populations.

Use 3 — Indicate a Sudden Break in Thought:

• I was about to leave when — wait, did you hear that?

The Pair Rule: If the aside is in the middle of a sentence, you need dashes on both sides:

• ✅ The mayor — beloved by residents — announced her retirement.
• ❌ The mayor — beloved by residents, announced her retirement. (Mismatched punctuation!)

If the aside is at the end of a sentence, you only need one dash:

• ✅ She had one dream — to become a scientist.

ACT Trap: The ACT frequently offers one answer with paired dashes and another with mismatched punctuation (one dash + one comma). Always check that pairs match.

Dashes — Choose the Correct Version 🔍

Parentheses

Parentheses de-emphasize information — they tell the reader, "This is a side note."

Use 1 — Supplementary Details:

• The study (conducted over three years) confirmed earlier findings.
• Marie Curie (1867–1934) won two Nobel Prizes.

Use 2 — Abbreviations or Acronyms:

• The Environmental Protection Agency (EPA) issued new guidelines.

Punctuation with Parentheses:

• Periods and commas go outside the closing parenthesis when the parenthetical is part of a larger sentence:
  • ✅ She passed the exam (with a perfect score), surprising everyone.
  • ❌ She passed the exam (with a perfect score,) surprising everyone.
• If the entire sentence is in parentheses, the period goes inside:
  • ✅ (She passed the exam with a perfect score.)

When to Use What — Decision Guide:

• Need to emphasize the aside? → Em dashes
• Need to de-emphasize / add a side note? → Parentheses
• Neutral — the most common, default choice? → Commas

ACT Tip: The ACT rarely tests parentheses directly, but when it does, it tests whether you can maintain consistent pairing and proper punctuation placement.

Identify the Correct Punctuation ✏️

Type "dash," "dashes," "parentheses," "commas," or "none" for the best choice in each sentence.

1. "The keynote speaker — a Nobel laureate ___ captivated the audience." — What should replace the blank to close the aside?

2. "The festival (held annually in October) ___ attracts visitors from across the country." — What punctuation, if any, goes in the blank?

3. "Three countries ___ France, Germany, and Italy ___ signed the agreement." — What paired punctuation best sets off this list in an emphatic way?

Quick-Check: Dashes & Parentheses 🔍

ACT-Style Passage Practice 📋

📌 End Punctuation & Quotation Marks

Part 5 of 7 — Periods with Quotes, Question Marks & Exclamation Points

End punctuation and quotation marks don't appear as often on the ACT as commas, but when they do, the rules are strict. Getting these right is easy — once you know the conventions.

The Basics:

ACT Approach: The ACT strongly prefers a neutral, academic tone. This means periods are almost always preferred over exclamation points. If an answer choice uses an exclamation point, it's usually wrong.

Quotation Marks & Punctuation Placement

Rule 1 — Periods and Commas Go INSIDE Quotation Marks (Always in American English):

• ✅ She said, "The experiment was a success."
• ✅ "The experiment was a success," she said.
• ❌ She said, "The experiment was a success". (Period outside — wrong!)

Rule 2 — Colons and Semicolons Go OUTSIDE Quotation Marks:

• ✅ He described the project as "groundbreaking"; others disagreed.
• ✅ She listed her "essentials": water, sunscreen, and a hat.

Rule 3 — Question Marks and Exclamation Points — It Depends:

• If the quote itself is a question: She asked, "Where is the library?"
• If the whole sentence is a question: Did she really say "I quit"?
• If both are questions, use one question mark inside: Did she ask, "Where is the library?"

Rule 4 — Titles of Short Works: Quotation marks enclose titles of short works (articles, poems, short stories, chapters):

• ✅ She read "The Raven" by Edgar Allan Poe.
• Longer works (books, films, newspapers) use italics, not quotes.

ACT Tip: On the ACT, periods and commas always go inside quotation marks. This is a hard rule — no exceptions in American English.

Quotation Marks — Spot the Error 🔍

End Punctuation — Periods, Question Marks & Exclamation Points

Periods — The Default: Most ACT passages use declarative sentences, so the period is the most common end mark. The ACT tests whether you can avoid creating:

• Run-on sentences (two sentences jammed together with no punctuation)
• Sentence fragments (ending a dependent clause with a period)

Run-on: ❌ The experiment succeeded the team celebrated. Fragment: ❌ Although the experiment succeeded. Correct: ✅ The experiment succeeded. The team celebrated.

Question Marks:

• Use for direct questions: What were the results?
• Do NOT use for indirect questions: ✅ She asked what the results were. (Period, not a question mark!)

Exclamation Points:

• Almost never correct on the ACT. Academic prose maintains a neutral tone.
• If you see an exclamation point in an answer choice, it's almost certainly wrong.

ACT Tip: When you see a period underlined, the ACT is testing whether a period is the right choice. Check: Is it a run-on? A fragment? Or a properly punctuated sentence?

End Punctuation Practice ✏️

What end punctuation mark should close each sentence? Type "period," "question mark," or "exclamation point."

1. "She wondered whether the results would be significant ___" — What goes in the blank?

2. "What factors contributed to the colony's decline ___" — What goes in the blank?

3. "The researchers published their findings in a peer-reviewed journal ___" — What goes in the blank?

Quick-Check: End Punctuation & Quotes 🔍

ACT-Style Passage Practice 📋

⚠️ Common ACT Punctuation Traps

Part 6 of 7 — Unnecessary Commas, Comma Splices & Run-On Sentences

The ACT isn't just testing whether you know where to put punctuation — it's also testing whether you know where to leave it out. Many of the trickiest ACT questions involve punctuation that seems right but is actually wrong.

The Three Most Common Traps:

Why These Are Tricky: When you read them aloud, they might "sound" okay. The ACT is testing your knowledge of the rules, not your ear.

Unnecessary Commas

Trap 1 — Comma Between Subject and Verb:

• ❌ The students in the advanced class, performed exceptionally well.
• ✅ The students in the advanced class performed exceptionally well.
• No comma should separate a subject from its verb.

Trap 2 — Comma Between Verb and Object:

• ❌ She discovered, that the results were inconclusive.
• ✅ She discovered that the results were inconclusive.
• No comma before "that" when it introduces an essential clause.

Trap 3 — Comma Before/After a Preposition:

• ❌ The results were consistent with, the earlier findings.
• ✅ The results were consistent with the earlier findings.

Trap 4 — Comma in a Compound Predicate (Two Verbs, One Subject):

• ❌ She reviewed the data, and published her results.
• ✅ She reviewed the data and published her results.
• This is NOT a compound sentence — there's only one subject. No comma before "and."

Trap 5 — Comma Between Two Items (Not a Series):

• ❌ He studied math, and science.
• ✅ He studied math and science.

ACT Strategy: When you see a comma in an underlined section, ask: "What is this comma separating?" If it's separating a subject from its verb, a verb from its object, or two items that don't form a series, it's unnecessary.

Unnecessary Commas — Keep or Delete? 🔍

Comma Splices & Run-On Sentences

Comma Splice: Two independent clauses joined by only a comma.

• ❌ The results were surprising, the team decided to repeat the experiment.
• This is WRONG because both halves are complete sentences.

Run-On (Fused Sentence): Two independent clauses with no punctuation at all.

• ❌ The results were surprising the team decided to repeat the experiment.

Five Ways to Fix a Comma Splice or Run-On:

ACT Trap — "However" Is NOT a FANBOYS:

• ❌ The sky was clear, however, rain was forecast. (Comma splice!)
• ✅ The sky was clear; however, rain was forecast.
• Words like however, therefore, moreover, consequently, furthermore are conjunctive adverbs. When one sits between two independent clauses, it needs a semicolon (or period) before it, not a comma.
• When "however" interrupts a single clause, a pair of commas is correct: ✅ Rain, however, was forecast. Cover "however" — if only one complete sentence remains, use commas.

ACT Strategy: When two complete thoughts appear in the same sentence, check the punctuation between them. A comma alone is never enough.

Fix the Error ✏️

Identify the punctuation error in each sentence. Type "comma splice," "unnecessary comma," or "run-on."

1. "The museum opened in 1985, it has since become one of the city's most popular attractions."

2. "The researchers conducted a thorough analysis, and concluded that the data supported the hypothesis."

3. "The concert was sold out fans lined up for hours hoping to get standing-room tickets."

Quick-Check: Punctuation Traps 🔍

ACT-Style Passage Practice 📋

🏆 Review & Mixed Practice

Part 7 of 7 — Punctuation Rules Cheat Sheet & Mixed ACT-Style Questions

You've now covered every major punctuation rule tested on the ACT English section. This final lesson reviews the key rules and challenges you with mixed-format questions that mimic real ACT passages.

ACT English Punctuation — Master Cheat Sheet:

ACT Punctuation Strategy Guide

Step 1 — Identify the Question Type: When you see punctuation underlined, categorize the question:

• Is it testing commas (series, introductory, nonessential)?
• Is it testing semicolons/colons (independent clauses)?
• Is it testing apostrophes (possession vs. contraction)?
• Is it testing matching pairs (dashes, parentheses)?
• Is it asking you to remove unnecessary punctuation?

Step 2 — Apply the Specific Rule: Each question type has a clear rule. Don't go by what "sounds right" — apply the rule mechanically.

Step 3 — Watch for the Trap Answer: The ACT often includes one answer that "sounds" correct but violates a rule. Common traps:

• Comma before "and" in a two-item construction
• Semicolon after a dependent clause
• Apostrophe in a possessive pronoun
• A dash opening an aside with a comma closing it

The "No Change" Reality: "No Change" is correct often enough that you should treat it as a real option, not a trap. Don't be afraid to choose it if the original is correct — but always verify by checking every rule that applies.

Time Management: The enhanced ACT English section gives you 35 minutes for 50 questions — about 42 seconds per question, with 4 answer choices each. Punctuation questions are usually the fastest to answer, so aim to finish them in well under that average (identify the rule, apply it, move on) and bank the extra time for rhetorical questions that require rereading the passage.

Mixed Review — Identify the Rule 🔍

Mixed Practice — Mini Passage

Read the following passage and consider the punctuation at each numbered point:

The Great Barrier Reef [1] which stretches over 1,400 miles along Australia's northeastern coast [2] is the world's largest coral reef system. Scientists have documented its decline over the past several decades [3] rising ocean temperatures, pollution, and overfishing have all contributed to the damage. Despite these challenges [4] conservation efforts have shown promising results [5] researchers recently reported that coral coverage in some areas has increased for the first time in years.

Correct punctuation at each point:

• [1] Comma — opens nonessential clause
• [2] Comma — closes nonessential clause
• [3] Period or semicolon — two independent clauses (comma here = comma splice)
• [4] Comma — after introductory phrase ("Despite these challenges")
• [5] Period, semicolon, or colon — two independent clauses (the second explains the first, so a colon also works)

This passage tests five rules in a single paragraph — a realistic representation of how the ACT combines punctuation concepts.

Mixed Practice — Name the Error ✏️

Identify the specific punctuation error in each sentence. Type "mismatched dashes," "apostrophe errors," or "unnecessary commas."

1. "The new library — designed by a world-famous architect, will open to the public in September."

2. "Its important to review you're notes before the exam begins."

3. "The coach praised the players' hard work, and encouraged them to keep practicing, and studying film."

Final Check: Master Rules 🔍

ACT-Style Mixed Practice — Final Challenge 📋