10.1 Commas, Semicolons & Apostrophes

10.1 Commas, Semicolons & Apostrophes

Quick Answer: Commas separate items in a series, set off introductory and nonrestrictive elements, and join independent clauses only when paired with a FANBOYS conjunction. Semicolons connect closely related independent clauses or introduce a conjunctive adverb (however, therefore). Apostrophes mark possession and contractions—not ordinary plurals. On PERT Writing, pick the revision that follows these standard mechanics without inventing new errors.

PERT Writing measures conventions of standard written English, including punctuation. You will not write an essay on test day; you will choose the sentence or revision that uses commas, semicolons, and apostrophes correctly. The traps are predictable: treating a conjunctive adverb like a coordinating conjunction, putting an apostrophe in a simple plural, or using only a comma between two complete sentences. This section gives you the rules that earn those points and a diagnosis routine you can run under time pressure.

Why Mechanics Matter on the PERT

Placement items often present four versions of the same sentence. Three usually look "almost right." The correct choice is the one that:

1. Keeps both independent clauses properly joined (or properly separated).
2. Does not add or remove necessary commas around nonessential information.
3. Uses apostrophes only for possession or contraction.

Memorize patterns, not vague advice like "use a comma when you pause." Pauses are unreliable; clause structure is not.

Commas: The High-Frequency Rules

1. Items in a Series (Lists)

Use commas to separate three or more items in a list of words, phrases, or clauses. College-style writing (and most PERT answer keys) expects the serial (Oxford) comma before the final and or or.

• The exam covers reading, writing, and mathematics.
• Students reviewed subject–verb agreement, pronoun case, and parallel structure.

Trap: Do not put a comma between only two coordinated items (The reading and, the writing sections is wrong).

2. Compound Sentences with FANBOYS

When a coordinating conjunction joins two independent clauses, place a comma before the conjunction. The seven coordinating conjunctions are FANBOYS: for, and, nor, but, or, yet, so.

• The writing section is untimed, but many students still set a pace.
• She finished the grammar set, so she moved on to word-choice items.

Critical distinction: If the second half does not have its own subject–verb pair that could stand alone, you usually omit the comma:

• She reviewed the handout and highlighted the rules. (second verb shares the subject She)
• She reviewed the handout, and she highlighted the rules. (two independent clauses)

3. Introductory Elements

Use a comma after an introductory word, phrase, or dependent clause that comes before the main clause.

• However, the cut score for writing is 103.
• After the practice test, he scheduled tutoring.
• Because the item tested punctuation, she reread every option carefully.
• In the final week of review, students focused on mechanics.

Short intro tip: A very short opener (Today she studied) is sometimes left uncommaed in informal prose, but on PERT prefer the clear, conventional comma after introductory phrases and clauses when options differ on that point.

4. Nonrestrictive (Nonessential) Information

Nonrestrictive material adds extra information that is not needed to identify the noun. Set it off with commas.

• My advisor, who works in building C, explained the exemptions.
• The handbook, updated for 2026, includes new sample items.

Restrictive material is essential to identify which one; do not use commas.

• Students who score below 103 may need developmental writing.
• The handbook that includes answer keys is on reserve.

Appositives follow the same idea: Dr. Rivera, the writing coordinator, led the workshop (nonrestrictive) versus the novelist Toni Morrison when the name is restrictive identity material in context.

Other Useful Comma Uses

• Coordinate adjectives: a clear, concise thesis (you could insert and or reverse the adjectives).
• Direct address: Maria, please revise the conclusion.
• Dates and places in full form: July 30, 2026, is the target date / Tallahassee, Florida, hosts many FCS campuses.

Comma Errors to Avoid

Semicolons

Independent Clauses

A semicolon can join two closely related independent clauses without a coordinating conjunction.

• The first draft was wordy; the revision was precise.
• Commas separate list items; semicolons separate complete thoughts.

Both sides of the semicolon must be able to stand as full sentences. If either side is a fragment, the semicolon is wrong.

Conjunctive Adverbs and Transitional Phrases

When you join independent clauses with a conjunctive adverb or transitional phrase, use a semicolon before it and a comma after it.

Common conjunctive adverbs: however, therefore, moreover, furthermore, nevertheless, consequently, otherwise, thus, instead, meanwhile.

• The score was close; however, she scheduled another attempt.
• He finished early; therefore, he checked every apostrophe.
• The item looked simple; in fact, it hid a comma splice.

Major PERT trap: Treating however like but.

• Wrong: She studied hard, however she still missed two items.
• Right: She studied hard; however, she still missed two items.
• Also right: She studied hard. However, she still missed two items.
• Also right: She studied hard, but she still missed two items.

However, therefore, and moreover are not FANBOYS. A comma alone before them creates a comma splice.

Semicolons in Complex Lists (Less Common on PERT)

If list items already contain commas, semicolons can separate the big units: The campuses are in Miami, Florida; Orlando, Florida; and Tampa, Florida. Know the pattern, but expect more items on simple IC joins and conjunctive adverbs.

Apostrophes

Possession

Do not use an apostrophe to form an ordinary plural: scores not score's; 1990s not 1990's in most academic style; CDs not CD's when you mean more than one CD.

Contractions

An apostrophe replaces omitted letters: don't (do not), can't (cannot), they're (they are), you're (you are), it's (it is / it has), who's (who is / who has).

On formal college writing and many PERT stems, full forms are fine, but if a choice uses a contraction, the apostrophe must be correct.

Its / It's and Other Classic Traps

• It's important to check its agreement rules.
• Who's responsible for the lab, and whose keys are these?

Plural of letters or unusual forms may take 's for clarity (mind your p's and q's), but ordinary word plurals do not.

Worked Diagnosis Routine

When a PERT item hinges on punctuation, run this checklist:

1. Count independent clauses. Underline each subject–finite-verb pair that could stand alone.
2. Check the join. Two ICs need a period, a semicolon, or comma + FANBOYS—not a bare comma, and not comma + however.
3. Test essential vs. extra. If the clause names which one, skip the commas; if it is bonus information, use commas.
4. Hunt apostrophes. Possession or missing letters? If neither, delete the apostrophe.
5. Read the winner aloud for meaning. The best mechanics choice should not scramble the logic of the sentence.

Sample Item Thinking

Stem: The writing center is open late however students still arrive unprepared.

• Two ICs: The writing center is open late / students still arrive unprepared.
• However is a conjunctive adverb, not FANBOYS.
• Correct revisions: …late; however, students… or …late. However, students… or …late, but students….

PERT-Style Traps

Quick Practice Patterns to Memorize

• List of three: A, B, and C.
• Compound sentence: IC, but IC.
• Intro clause: Because…, IC.
• Nonrestrictive: noun, who…, verb.
• Related ICs: IC; IC.
• Transition join: IC; therefore, IC.
• Possession: singular 's, plural s'.
• Never: its' as a standard form; use its or it's.

Master these patterns and you can eliminate two options on many mechanics items before you even compare subtle wording. Punctuation on the PERT is less about rare style points and more about applying a short list of college-ready rules consistently.