Punctuation

Punctuation questions on the ACT English section test your knowledge of how commas, semicolons, colons, apostrophes, dashes, and other marks should be used in standard written English. These questions appear frequently, and knowing a handful of key rules can help you answer them quickly and accurately.

Commas

Commas are by far the most commonly tested punctuation mark on the ACT. Key rules include:

• Items in a series: Use commas to separate three or more items. "She bought apples, oranges, and bananas."
• Introductory elements: Place a comma after introductory words, phrases, or clauses. "After the storm, the streets were flooded."
• Non-restrictive (non-essential) clauses: Set off with commas. "My brother, who lives in Texas, is visiting." If you can remove the clause without changing the core meaning, use commas.
• Restrictive (essential) clauses: Do NOT use commas. "The student who scored highest received the award." The clause identifies which student.
• Compound sentences: Use a comma before a coordinating conjunction (FANBOYS) that joins two independent clauses. "I studied hard, but I still struggled."
• Do NOT place a comma between a subject and its verb or between a verb and its direct object.

Additional comma examples:

• Coordinate adjectives: "She wore a long, elegant dress." (You can say "long and elegant" so the comma is correct.) But: "She wore a bright red dress." (NOT "bright, red" — "bright" modifies "red," not "dress" independently.)
• Appositives: "My friend, a talented musician, performed at the concert." The appositive "a talented musician" is extra information and needs commas.
• Comma + FANBOYS vs. no comma: "I studied hard, and I passed the test." (Two independent clauses → comma.) "I studied hard and passed the test." (One subject, two verbs → NO comma.)

Semicolons

A semicolon joins two independent clauses that are closely related in meaning, without a coordinating conjunction.

• "The experiment failed; the team had to start over."
• Use a semicolon before conjunctive adverbs (however, therefore, moreover) followed by a comma: "The data was incomplete; however, the results were promising."
• Key rule: Both sides of a semicolon must be complete sentences. If one side is a fragment, the semicolon is wrong.

Example — testing yourself:
Which is correct?
(A) "The rain stopped; we went outside."
(B) "The rain stopped; and we went outside."
(C) "The rain stopped; going outside."
Answer: (A). Both sides are independent clauses. (B) adds an unnecessary "and" after the semicolon. (C) has a fragment on the right side.

More semicolon examples:

• Correct: "The mayor proposed the plan; the council approved it unanimously." (Two complete sentences, closely related.)
• Incorrect: "The mayor proposed the plan; which the council approved." ("Which the council approved" is a dependent clause, not an independent clause.)
• With conjunctive adverb: "She trained for months; consequently, she finished the marathon with ease."

Colons

A colon introduces a list, explanation, or elaboration. The clause before the colon must be an independent clause.

• "She needed three things: a pen, a notebook, and determination."
• "The answer was obvious: they had to leave immediately."
• Do NOT use a colon after "such as," "including," or "for example" — these words already serve the introductory function.
• Do NOT use a colon after a verb or preposition: ✗ "The ingredients are: flour, eggs, milk." The correct version omits the colon.

Additional colon examples:

• Correct: "The museum featured works by three Impressionists: Monet, Renoir, and Degas."
• Incorrect: "The museum featured works by: Monet, Renoir, and Degas." (A colon cannot follow a preposition like "by.")
• Correct — explanation: "The verdict surprised no one: the evidence had been overwhelming from the start."

Apostrophes

Apostrophes indicate possession or contraction.
More apostrophe examples:

• "The company's profits rose sharply." (singular possessive — the profits belong to one company)
• "The two companies' merger was announced." (plural possessive — the merger involves two companies)
• "It's been a long day." = "It has been a long day." (contraction) vs. "The cat licked its paw." (possessive, no apostrophe)

Dashes

Em dashes (—) set off parenthetical information with more emphasis than commas. They come in pairs or singly at the end of a sentence.

• "The results — which surprised everyone — were published immediately."
• If a sentence opens with one dash, it must close with another dash (or the clause must end the sentence).
• Dashes can replace colons for dramatic effect: "She had one goal — to win."
• ACT trap: Mixing a dash with a comma is always wrong. "The results — which surprised everyone, were published" needs a second dash, not a comma.

Additional dash examples:

• Correct pair: "The three cities — London, Paris, and Tokyo — are all major financial centers."
• Incorrect mix: "The three cities — London, Paris, and Tokyo, are all major financial centers." (Started with a dash, closed with a comma. Must match.)
• Single dash at end: "She had only one thing on her mind — sleep."

Periods, Question Marks, and Exclamation Points

These end-of-sentence marks are less commonly tested, but keep in mind:

• A period ends a declarative or imperative sentence.
• A question mark ends a direct question (not an indirect one: "She asked whether he was coming" — no question mark).
• Exclamation points are rarely appropriate in formal writing. If you see one as an answer choice on the ACT, it is almost certainly wrong.

Unnecessary Punctuation

The ACT frequently tests whether punctuation should be removed entirely. Common traps:

• A comma between a subject and verb: "The tall, graceful dancer, performed beautifully." (Remove the comma after "dancer.")
• A comma before "that" in a restrictive clause: "The book, that I borrowed, was excellent." (Remove both commas.)
• An apostrophe in a simple plural: "The teacher's gave the exam." (Should be "teachers.")
• A semicolon before a fragment: "She enjoyed the concert; especially the final song." (Use a comma or dash instead.)

Common Mistakes: Top 5 ACT Punctuation Traps

1. Comma splice: Joining two independent clauses with only a comma. "The sun set, the stars appeared." Fix with a period, semicolon, or comma + FANBOYS.
2. Semicolon before a fragment: "She loved the movie; especially the ending." The part after the semicolon is not a complete sentence. Use a comma or dash instead.
3. Colon after an incomplete sentence: "The ingredients include: flour and sugar." Remove the colon — "include" makes the clause incomplete before the colon.
4. Its vs. it's: "The company raised it's prices." Wrong — "it's" means "it is." The possessive form is "its" (no apostrophe).
5. Mismatched dash and comma: "The city — a bustling metropolis, attracted millions of tourists." The dash must close with another dash, not a comma.

"NO CHANGE" Strategy

On the ACT English section, the first answer choice (A or F) is always "NO CHANGE." For punctuation questions specifically:

• If the original punctuation follows all the rules — correct comma placement, proper semicolon use, matched dash pairs — then NO CHANGE is right. Do not overthink it.
• The most common reason NO CHANGE is correct on punctuation questions: the other options add unnecessary punctuation (extra commas, rogue semicolons) where none is needed.
• Quick test: Read the sentence as written. Does it flow naturally with no grammatical issues? Then scan the other choices. If they all introduce problems, pick NO CHANGE.
• NO CHANGE appears as the correct answer roughly 25% of the time across the entire test. Do not avoid it.

Practice Walkthrough

ACT-style passage question — work through it step by step:

Passage excerpt: "The artist, who had been working in obscurity for decades, finally received recognition when a prominent gallery displayed her paintings."

(F) NO CHANGE
(G) decades;
(H) decades
(J) decades —

Step 1 — Identify the structure: "who had been working in obscurity for decades" is a non-essential (non-restrictive) clause. It adds extra information about the artist. The sentence makes sense without it: "The artist finally received recognition..."
Step 2 — Apply the rule: Non-essential clauses must be set off by matching punctuation. The clause opens with a comma (after "artist,"), so it must close with a comma.
Step 3 — Evaluate each choice:

• (F) NO CHANGE — closes with a comma, matching the opening comma. Correct.
• (G) Semicolon — mismatches with the opening comma and creates a structural error. Wrong.
• (H) No punctuation — leaves the non-essential clause unclosed. Wrong.
• (J) Dash — mismatches with the opening comma. Wrong.

Answer: (F) NO CHANGE

Tips for the ACT

• Identify structures: When you see a punctuation question, determine the grammatical structures on both sides of the mark.
• Less is more: If removing the punctuation makes the sentence correct, that is often the right answer.
• Semicolons = periods: Both connect two independent clauses. If a period would work, a semicolon works (and vice versa).
• Apostrophe check: Possession vs. contraction vs. unnecessary apostrophe is a top ACT trap.
• Dash pairs: If two dashes open a parenthetical, both must be present. Mixing a dash with a comma is always wrong.
• Colon rule: What comes before a colon must be a complete sentence. If it's not, the colon is wrong.
• When stuck: Read the sentence aloud without the punctuation. If it flows naturally, the punctuation may be unnecessary.
• Elimination shortcut: With 4 choices, if you can identify the grammatical structure (independent clause, fragment, etc.) on each side of the punctuation, you can usually eliminate 2-3 choices immediately.
• Speed hack: Punctuation questions are usually the fastest on the ACT. Master these rules and aim for 20-30 seconds per punctuation question to bank time for harder rhetorical questions.