Avoiding Run-On Sentences with Simple Fixes

Run-on sentences are one of the most common grammar mistakes people make in writing. They appear in everyday conversations, school essays, blog posts, business emails, and even in professional publications.

Yet many people do not realize they are writing them. Why? Because in speech, our pauses, tone, and breathing patterns help our listeners understand where one idea ends and the next begins.

But when it comes to writing, punctuation and sentence structure take over that job. If they’re missing or wrong, your writing becomes confusing, jumbled, or just hard to follow.

In this guide, we’ll explore what run-on sentences are, why they happen, how to fix them, and how to avoid them altogether. You’ll also see plenty of real examples, clear solutions, and practical tips to help you recognize and correct them confidently.

READ: Avoiding Comma Mistakes Before “Because”

What is a Run-On Sentence?

A run-on sentence is when two or more independent clauses (complete sentences) are joined together incorrectly. They either lack the right punctuation, the right connector (conjunction), or both. Run-ons ignore the natural pause or separation that should exist between complete thoughts.

Let’s break that down:

An independent clause is a group of words that contains a subject and a verb and expresses a complete thought. It can stand alone as a sentence.

A run-on occurs when you stick two independent clauses together without using the right punctuation or connector.

Two common types of run-on sentences:

1. Fused Sentences: No punctuation or conjunction is used between the independent clauses.

   Example:
   I love pizza it’s my favorite food.
   This sentence tries to cram two thoughts into one line with no pause.

2. Comma Splices: A comma is used between the clauses, but no conjunction.

   Example:
   She was tired, she went to bed early.
   The comma here is not enough on its own to join the sentences.

Why Are Run-On Sentences a Problem?

Run-on sentences make writing unclear. They can confuse your reader or force them to reread the sentence to figure out what it means. In professional and academic writing, they weaken your credibility.

In business communication, they can lead to misunderstandings. Readers need clarity. Sentences need rhythm. Without proper structure, your ideas get lost.

READ: Correct Use of “Who” vs. “Whom” – A Simple, Practical Guide for Everyone

Simple Fixes for Run-On Sentences

Let’s now explore five easy ways to fix run-on sentences, with practical examples and clear explanations.

1. Use a Period to Separate Sentences

If both parts of the run-on are complete sentences, the easiest fix is to split them into two.

Example:
Wrong: I finished the project it was due today.
Fix: I finished the project. It was due today.

This method creates two clear, complete thoughts. Use it when you want a clean break between ideas.

2. Use a Comma with a Coordinating Conjunction

Coordinating conjunctions include: for, and, nor, but, or, yet, so. Use the acronym FANBOYS to remember them. To fix a run-on, you can join two independent clauses with a comma and one of these words.

Example:
Wrong: He didn’t study, he still passed the test.
Fix: He didn’t study, but he still passed the test.

This method shows how the two ideas are connected logically.

3. Use a Semicolon Between Closely Related Sentences

A semicolon is stronger than a comma but weaker than a period. Use it when the two sentences are closely related in meaning and tone.

Example:
Wrong: We went to the market it was already closed.
Fix: We went to the market; it was already closed.

Semicolons are great when you want to avoid the abruptness of a full stop but still need to keep clarity.

4. Use a Subordinating Conjunction

Subordinating conjunctions turn one of the clauses into a dependent clause, making the sentence grammatically correct.

Common subordinating conjunctions: because, although, since, unless, after, before, while, when.

Example:
Wrong: She was late she missed the bus.
Fix: She was late because she missed the bus.

This method helps you show cause-effect, contrast, condition, or time relationships.

5. Use a Conjunctive Adverb with Proper Punctuation

Words like however, therefore, moreover, nevertheless, and consequently are conjunctive adverbs. They need a semicolon before them and a comma after.

Example:
Wrong: He was very tired he continued working.
Fix: He was very tired; however, he continued working.

These transitions are useful for formal writing and show smooth flow between ideas.

READ: When to Use “Then” vs. “Than”

Quick Guide: Fixing Run-On Sentences

How to Avoid Run-On Sentences

Avoiding run-on sentences means developing an eye for spotting when a sentence tries to carry more than it should without support. Here are some strategies:

1. Read your writing aloud. If you run out of breath or feel like you’re cramming too much in one line, it may be a run-on.

2. Check for multiple subjects and verbs. If your sentence has more than one subject doing an action, verify if they are properly connected.

3. Use punctuation wisely. Commas do not glue full sentences together on their own.

4. Break long thoughts into smaller parts. Especially if clarity or flow is suffering.

5. Look for signal words. If you see a coordinating or subordinating conjunction, make sure it is used correctly.

Real-Life Examples of Run-Ons and Fixes

Example 1
Run-On: The game was exciting everyone stayed to watch the final round.
Fix: The game was exciting, so everyone stayed to watch the final round.
Explanation: We added a comma and the conjunction “so” to make the connection clear.

Example 2
Run-On: He opened the door it was completely dark inside.
Fix: He opened the door. It was completely dark inside.
Explanation: The two complete thoughts were separated for clarity.

Example 3
Run-On: They were exhausted they had been working for ten hours.
Fix: They were exhausted because they had been working for ten hours.
Explanation: We used “because” to show cause and make one idea dependent on the other.

Example 4
Run-On: She called me I didn’t answer.
Fix: She called me, but I didn’t answer.
Explanation: The coordinating conjunction “but” with a comma joins the clauses correctly.

READ: Is It “Its” or “It’s”?

Frequently Asked Questions (FAQs)

Q1: Are run-on sentences the same as long sentences?
No. A sentence can be long and still be correct if it is properly structured. A run-on sentence is defined by incorrect grammar, not length. Even short sentences can be run-ons.

Q2: Is using a comma enough to join two complete sentences?
Not always. A comma by itself creates a comma splice. You need a coordinating conjunction or use a semicolon.

Q3: Can I start a sentence with a conjunction to avoid a run-on?
Yes, especially in informal writing. Starting a sentence with “and” or “but” is now acceptable in most forms of writing. Just make sure it’s clear and grammatically correct.

Q4: What if my sentence sounds fine when I say it out loud?
Speech allows natural pauses, but writing requires punctuation to guide the reader. If you’re unsure, check if each part of the sentence can stand alone as a full sentence.

Q5: How can I teach children or students to avoid run-ons?
Use color coding. Mark each subject and verb, and then check if two full ideas are squeezed into one. Practice rewriting them with different methods: periods, conjunctions, semicolons.

Final Thoughts

Run-on sentences are not just grammar issues. They affect how people understand your message. When your sentences are clear and properly punctuated, your writing becomes easier to read, more professional, and more persuasive.

The key to avoiding run-ons is simple: know where one thought ends and the next begins, and use the right tools to make that clear. Whether you are a student, professional, or casual writer, mastering this skill will make a big difference in the way you communicate.

Keep reading. Keep practicing. And always let your sentences breathe.