Fixing Run-ons and Fragments

Now that you can identify run-on sentences and fragments, it is time to learn how to fix them. This section presents concrete strategies with before-and-after examples for each type of error. Every strategy is a tool in your editing toolkit -- different situations call for different fixes.

Part 1: Fixing Run-on Sentences

There are five main strategies for fixing run-ons. Each produces a grammatically correct sentence, but they create different effects in terms of emphasis, flow, and relationship between ideas.

Strategy 1: Separate into Two Sentences (Period)

The simplest fix: place a period where the two independent clauses meet, creating two separate sentences.

When to use this strategy: When the two ideas are related but distinct, and you want short, punchy sentences. This strategy is excellent for emphasis.

Watch out for: Overuse. Too many short sentences in a row creates a choppy, monotonous rhythm. Vary this strategy with others.

Strategy 2: Use a Semicolon

A semicolon signals that two independent clauses are closely related in meaning. It creates a stronger connection than a period but still marks a clear boundary.

When to use this strategy: When the two clauses are closely related and you want to show that connection without using a conjunction. The semicolon says: "These two ideas go together."

Rule: The clause after the semicolon begins with a lowercase letter (unless the first word is a proper noun).

Strategy 3: Add a Comma + Coordinating Conjunction (FANBOYS)

Join the two clauses with a comma followed by one of the seven coordinating conjunctions: for, and, nor, but, or, yet, so (remembered by the acronym FANBOYS).

Choosing the right conjunction:

Important: You need both the comma and the conjunction. A comma alone creates a comma splice. A conjunction alone (without the comma) is technically acceptable in very short clauses but is considered informal.

Strategy 4: Use a Semicolon + Transitional Expression

Join the clauses with a semicolon, a transitional word or phrase, and a comma. Common transitional expressions include: however, therefore, moreover, furthermore, consequently, nevertheless, meanwhile, instead, in addition, for example, in fact, on the other hand, as a result.

Pattern: Independent clause ; transitional expression , independent clause.

Common mistake: Using a comma instead of a semicolon before the transitional expression. This creates a comma splice:

He studied all night, however, he still felt unprepared. (comma splice)

He studied all night**;** however, he still felt unprepared. (correct)

Strategy 5: Subordinate One Clause

Turn one of the independent clauses into a dependent clause by adding a subordinating word (because, although, when, if, since, while, after, before, unless, etc.). This strategy is especially powerful because it shows the relationship between the two ideas.

When to use this strategy: When one idea is the cause, condition, time frame, or background for the other. Subordination helps the reader understand how the ideas are related, not just that they are.

Punctuation note: When the dependent clause comes first, follow it with a comma. When it comes second, a comma is usually not needed.

Because the experiment failed**,** the researchers started over. (dependent clause first --> comma)

The researchers started over because the experiment failed. (dependent clause second --> no comma)

Comparing the Five Strategies

Here is the same run-on fixed five different ways:

Original run-on: The presentation was excellent the audience applauded loudly.

All five are correct. The best choice depends on the emphasis you want, the relationship between the ideas, and the rhythm of your surrounding sentences.

Part 2: Fixing Fragments

The strategy for fixing a fragment depends on what type of fragment it is. In every case, you either add what is missing or attach the fragment to a neighboring sentence.

Fixing Missing-Subject Fragments

Add a subject, or combine the fragment with the previous sentence.

Fixing Missing-Verb Fragments

Add a verb to make the fragment a complete sentence, or attach it to a neighboring sentence.

Fixing Dependent Clause Fragments

Attach the dependent clause to a main clause, or remove the subordinating word.

Fixing Participial Phrase (-ing / -ed) Fragments

Add a subject and helping verb, attach to a main clause, or rewrite with a finite verb.

Fixing Infinitive Phrase Fragments

Attach the infinitive phrase to a main clause, or make it the subject of a complete sentence.

Fixing Afterthought and List Fragments

Attach to the previous sentence with appropriate punctuation.

Mixed Practice: Identify and Fix

Each sentence below contains either a run-on or a fragment. Identify the error type, then fix it. Suggested answers follow.

1. The library closes at nine we need to leave soon.
2. Working on the project all weekend without a break.
3. Although she had studied for weeks.
4. The traffic was heavy, we arrived late to the meeting.
5. To earn a promotion at the company.
6. She passed the exam she was relieved.
7. The documentary about climate change.
8. He enjoys cooking, his wife prefers baking.
9. Because the server crashed during peak hours.
10. The results were surprising they contradicted the initial hypothesis.

Answers:

1. Fused sentence. Fix: The library closes at nine**;** we need to leave soon.
2. Participial phrase fragment. Fix: She was working on the project all weekend without a break. (Or: Working on the project all weekend without a break, she finished ahead of schedule.)
3. Dependent clause fragment. Fix: Although she had studied for weeks, she still felt nervous about the exam.
4. Comma splice. Fix: The traffic was heavy**, so** we arrived late to the meeting.
5. Infinitive phrase fragment. Fix: To earn a promotion at the company, he took on extra responsibilities.
6. Fused sentence. Fix: She passed the exam**.** She was relieved. (Or: She passed the exam**, and** she was relieved.)
7. Missing-verb fragment. Fix: The documentary about climate change was eye-opening.
8. Comma splice. Fix: He enjoys cooking**;** his wife prefers baking. (Or: He enjoys cooking**, but** his wife prefers baking.)
9. Dependent clause fragment. Fix: Because the server crashed during peak hours, the website was unavailable for two hours.
10. Fused sentence. Fix: The results were surprising**;** they contradicted the initial hypothesis.

Quick Summary

Run-ons and Fragments Quick Reference

This section is a condensed reference guide. Use it when editing your writing or reviewing before an exam. It contains the key patterns, rules, common traps, and a self-editing checklist -- everything from the previous two sections distilled into a quick-access format.

Run-on Sentence Patterns

How to Recognize Them

Five Ways to Fix a Run-on

The Seven Coordinating Conjunctions (FANBOYS)

Rule: When joining two independent clauses, always place a comma before the coordinating conjunction.

Common Transitional Expressions

Rule: Transitional expressions are not conjunctions. They cannot join two independent clauses with just a comma. Always use a semicolon before them (or start a new sentence).

The data was clear, therefore we proceeded. (comma splice)

The data was clear**;** therefore**,** we proceeded. (correct)

The data was clear**.** Therefore**,** we proceeded. (also correct)

Fragment Patterns

How to Recognize Them

How to Fix Each Type

Subordinating Words Reference

If a clause begins with one of these words, it is a dependent clause and cannot stand alone:

Common Traps and Mistakes

Trap 1: Confusing Transitional Expressions with Conjunctions

Words like however, therefore, moreover, and consequently are not coordinating conjunctions. They cannot fix a run-on when preceded by only a comma.

Trap 2: Long Sentences That Are Actually Run-ons

A sentence can be long and still be correct, or it can be long because it is a run-on. Length alone does not determine correctness. Always check for proper connections between independent clauses.

Run-on (long but incorrect): The research team collected data from over 500 participants across three continents and analyzed the results using advanced statistical methods, the findings suggested a significant correlation between exercise frequency and cognitive performance in adults over 50.

This sentence has two independent clauses joined by only a comma after "methods." Fix it with a semicolon or period at that point.

Trap 3: Short Sentences That Are Actually Fragments

A sentence can be short and still be complete, or it can be short because it is a fragment. Length alone does not tell you.

Always apply the three-question test regardless of sentence length.

Trap 4: "Which" and "Who" Fragments

Relative clauses beginning with which, who, whom, or that are dependent clauses and cannot stand alone.

Trap 5: "Such as," "For example," and "Especially" Fragments

These phrases introduce details that belong to the previous sentence. They are not sentence starters.

Self-Editing Checklist

Use this checklist every time you proofread an essay, email, or any piece of formal writing. Go through your text sentence by sentence.

For Each Sentence, Check:

• Subject present? Can I identify who or what the sentence is about?
• Complete verb present? Does the sentence have a finite verb (not just an -ing word, infinitive, or past participle without a helper)?
• Complete thought? Does the sentence make full sense on its own, or does it start with a subordinating word (because, although, when, if, which, who) without connecting to an independent clause?
• One independent clause only, or properly joined? If the sentence contains two or more independent clauses, are they connected with (a) a period, (b) a semicolon, (c) a comma + FANBOYS conjunction, (d) a semicolon + transitional expression, or (e) subordination?
• No comma splices? If I see a comma between what look like two complete thoughts, is there also a coordinating conjunction (FANBOYS) after the comma? If not, I need a semicolon, period, or conjunction.
• Afterthoughts attached? Phrases starting with "such as," "especially," "for example," "including," or "except" are joined to the main sentence, not standing alone.

Quick Decision Flowchart

Step 1: Read the sentence. Does it have a subject and a complete verb?

• No --> It is a fragment. Add the missing element or attach to a neighboring sentence.
• Yes --> Go to Step 2.

Step 2: Does the sentence begin with a subordinating word (because, although, when, if, who, which, etc.)?

• Yes, and there is no independent clause --> It is a fragment. Attach to a main clause or remove the subordinating word.
• No, or yes and there is a main clause --> Go to Step 3.

Step 3: Does the sentence contain two or more independent clauses?

• No --> The sentence is likely correct. Move on.
• Yes --> Go to Step 4.

Step 4: How are the independent clauses connected?

• Period or semicolon --> Correct.
• Comma + FANBOYS --> Correct.
• Semicolon + transitional expression + comma --> Correct.
• Subordination (one clause made dependent) --> Correct.
• Nothing (fused) --> Run-on. Apply one of the five fixing strategies.
• Comma only (no conjunction) --> Comma splice. Apply one of the five fixing strategies.

At-a-Glance Error Examples

These are the most common run-on and fragment patterns you will encounter. Bookmark this table for quick reference.

Key Rules to Remember

1. A comma cannot join two independent clauses by itself. Always add a FANBOYS conjunction, or use a semicolon or period instead.
2. Transitional words (however, therefore, moreover) are not conjunctions. Use a semicolon before them when they sit between two independent clauses.
3. Every sentence needs a subject, a complete verb, and a complete thought. If any one of these is missing, it is a fragment.
4. A dependent clause cannot stand alone. If a sentence starts with a subordinating word, make sure it connects to an independent clause.
5. An -ing word is not a complete verb without a helping verb. "Running" is not a verb by itself; "is running" or "was running" is.
6. When in doubt, read the sentence aloud. If it sounds like it trails off or needs more information, it may be a fragment. If it sounds like two sentences jammed together, it may be a run-on.