9.1 Fragments, Run-ons & Comma Splices

9.1 Fragments, Run-ons & Comma Splices

Quick Answer: A complete sentence expresses a full thought with at least one independent clause (subject + finite verb). Fragments lack that completeness. Run-ons smash two independent clauses together with no correct join: a fused sentence uses nothing, and a comma splice uses only a comma. Fix them with a period, a semicolon, a comma plus a coordinating conjunction (FANBOYS), or subordination.

Sentence-structure items on the PERT Writing section test whether you can spot and repair nonstandard joins. You will not write an essay on test day; instead, you choose the revision that produces clear, complete, conventional college English. Mastering clauses is the fastest path to those points.

Independent Clauses Versus Dependent Clauses

An independent clause has a subject and a finite verb and can stand alone as a sentence.

• Independent: The placement advisor reviewed my scores.
• Independent: Students may retake the writing section.

A dependent (subordinate) clause also has a subject and verb, but a subordinating word makes it incomplete by itself. Common subordinators include because, although, when, if, since, while, after, before, unless, until, that, which, who, and whose.

• Dependent: Because the placement advisor reviewed my scores
• Dependent: When students may retake the writing section

A phrase is not a clause at all—it lacks a subject–finite-verb pair. -ing phrases (Walking into the lab), prepositional phrases (After the exam), and infinitive phrases (To improve placement) are common fragment material when writers treat them as full sentences.

Test tip: Cover the subordinating word. If what remains could be a sentence, you started with a dependent clause, not a fragment from missing a verb—but it is still incomplete until you attach an independent clause.

Sentence Fragments

A fragment is a group of words punctuated as a sentence that cannot stand alone. PERT items often present fragments in multiple-choice revisions; you must pick the option that completes the thought without creating a new error.

Common Fragment Patterns

1. Missing subject: Went to the tutoring center after class. → Who went?
2. Missing finite verb: The students in the writing lab every afternoon. → What about them?
3. Dependent clause alone: Although the essay had strong evidence. → Then what?
4. -ing or to phrase alone: Hoping to raise her score. / To finish before noon.
5. Example or list add-on: Such as commas, semicolons, and periods. (needs an independent clause)
6. Relative clause alone: Which surprised the instructor.

How to Fix Fragments

• Attach the fragment to a nearby independent clause with correct punctuation: Although the essay had strong evidence, the conclusion needed work.
• Add the missing subject or finite verb: She went to the tutoring center after class.
• Drop the subordinating word if the clause should stand alone: The essay had strong evidence. (only when meaning allows)

Do not “fix” a fragment by merely capitalizing it or adding a period. Completeness is about structure, not capitalization.

Run-ons: Fused Sentences and Comma Splices

A run-on occurs when two (or more) independent clauses are joined incorrectly.

Writers create fused sentences when they rush; they create comma splices when they sense a pause but use only a comma. Both are nonstandard in academic English and are frequent PERT targets.

Not every long sentence is a run-on. A long sentence with one independent clause plus modifiers is fine. A short sentence can still be a fused sentence if it illegally joins two independent clauses: I studied she slept.

Not every comma is a splice. Commas correctly separate items in a list, set off nonessential information, or follow introductory elements. A splice specifically joins two independent clauses with only a comma and no coordinating conjunction.

Four Standard Ways to Fix Run-ons

Memorize these four repairs. PERT answer choices often differ only by which legal method they use—and one option may change meaning or create a fragment.

Method 1: Period (Two Sentences)

Split into two complete sentences.

• Error: The lab opens at eight, students line up early.
• Fix: The lab opens at eight. Students line up early.

Use this when the ideas are closely related but can stand alone cleanly. Avoid choppy strings of very short sentences if a better join exists—but on multiple-choice items, two correct short sentences beat one illegal join.

Method 2: Semicolon

Join two closely related independent clauses with a semicolon. No coordinating conjunction is required.

• Fix: The lab opens at eight; students line up early.

A semicolon can also pair with a conjunctive adverb (however, therefore, moreover, consequently, nevertheless, then, thus) plus a comma:

• Fix: The cut score is 103; therefore, she scheduled extra practice.

Do not use a comma alone with however: The cut score is 103, however, she scheduled extra practice is still a comma-splice pattern (or a punctuation error). Prefer …103; however, she… or …103. However, she….

Method 3: Comma + Coordinating Conjunction (FANBOYS)

The coordinating conjunctions are for, and, nor, but, or, yet, so. Pattern: independent clause + comma + FANBOYS + independent clause.

• Fix: The lab opens at eight, so students line up early.
• Fix: She knew the rule, but she still wrote a comma splice.

Common mistakes:

• Missing the comma: She knew the rule but she still wrote a comma splice. (often marked informal; many tests prefer the comma with two full clauses)
• Using a FANBOYS word without two full clauses: She studied hard, but tired. → tired is not an independent clause.
• Using however as if it were FANBOYS: however is not a coordinating conjunction.

Method 4: Subordination

Turn one clause into a dependent clause with a subordinating conjunction or relative pronoun. This is often the best stylistic fix when one idea should support the other.

• Fix: Because the lab opens at eight, students line up early.
• Fix: Students line up early when the lab opens at eight.
• Fix: The student who arrived first secured a quiet carrel.

Subordination shows logical relationships (cause, time, contrast, condition). On PERT, choose subordination when the options ask for the most effective combination and one idea clearly depends on the other.

Worked Diagnosis Routine

When a PERT item highlights a sentence or offers four revisions, run this checklist:

1. Find finite verbs and subjects. Underline each clause’s core.
2. Count independent clauses. Zero complete ICs → fragment risk. Two ICs → check the join.
3. Inspect the boundary. Nothing? Fused. Only a comma? Splice. Subordinator alone? Fragment.
4. Apply one of the four fixes without changing the original meaning unless the prompt asks for improvement of logic.
5. Reject traps: options that fix the run-on but introduce a fragment, wrong their/there, or a new agreement error.

Sample Item Thinking

Original: Maria finished the practice set she forgot to review the explanations.

• Two ICs: Maria finished the practice set + she forgot to review the explanations.
• Join: nothing → fused sentence.
• Strong fixes: period; semicolon; …set, but she forgot…; After Maria finished the practice set, she forgot… (subordination works if the timing relationship is intended).

Original: Although she reviewed the explanations.

• Dependent clause only → fragment. Attach: Although she reviewed the explanations, she still missed parallel-structure items.

PERT-Style Traps

• Polite-sounding splices: It is raining, we should leave early. Sounds natural in speech; still a splice in standard writing.
• "Then" is not FANBOYS: He opened the booklet, then he read the directions is still a splice (or needs a semicolon / and then).
• Command + statement: Stop writing the time is up is fused; Stop writing. The time is up is correct.
• Quotes and titles do not excuse missing joins between surrounding independent clauses.
• Over-correction: Turning a correct complex sentence into choppy fragments is not an improvement.

Quick Practice Patterns to Memorize

Sentence boundaries are the foundation for modifiers and parallel structure in the next sections: if you cannot find the independent clause, you cannot place modifiers or keep lists parallel. Build the habit of marking subjects and verbs on every writing item—even when the question looks like “style,” completeness still rules.