Share on FacebookShare on TwitterShare on LinkedinShare via emailShare via Facebook Messenger

How to Fix and Prevent Run-on Sentences

Updated on January 16, 2024Grammar

A run-on sentence is a common English writing mistake that happens when a sentence incorrectly connects clauses. People write run-on sentences all the time, but luckily they’re easy to correct. In this guide, we explain everything you need to know about run-on sentences, including how to fix them.

Give your writing extra polish
Grammarly helps you communicate confidently

Table of Contents

What are run-on sentences?

3 ways to fix a run-on sentence

Examples of run-on sentences and how to fix them

Types of run-on sentences

Run-on sentences FAQs

What are run-on sentences?

To understand run-on sentences, you first have to understand independent and dependent clauses. A clause is a basic unit of language that includes a subject and a predicate (which requires at least one verb). A single clause alone, with proper punctuation, is a complete sentence.

I fell asleep.

The TV woke me up.

If you want to connect two or more clauses together in English, you need to use the right grammar. Usually, you can connect clauses correctly by adding a comma with a conjunction or adding a semicolon to the sentence.

I fell asleep, but the TV woke me up.

I fell asleep; the TV woke me up.

If you don’t connect the clauses with a semicolon or comma with a conjunction, the sentence is incorrect. These mistakes are called run-on sentences.

I fell asleep the TV woke me up. 

Likewise, if you use too many conjunctions or use them incorrectly (for example, without the comma), that’s also a run-on sentence.

I fell asleep but the TV woke me up and now I want to sleep again but I can’t. 

3 ways to fix a run-on sentence

1 Divide the clauses into two sentences

Often in writing, the best way to fix a run-on sentence is to split it into two or more separate sentences. Be sure to capitalize the first letter of each sentence and use a period, question mark, or exclamation point between them.

Our training was successful we won our first game! 

Our training was successful! We won our first game! 

2 Insert a semicolon between the two clauses

Another way to write better sentences is by using a semicolon to connect two clauses in the same sentence. This works great for comma splices because you can simply replace the comma with a semicolon.

It hasn’t rained in weeks, my flowers are turning brown. 

It hasn’t rained in weeks; my flowers are turning brown. 

3 Use a comma and a conjunction

Conjunctions work well for describing the relationship between two clauses. You can use either a coordinating conjunction (for, and, nor, but, or, yet, and so) or a subordinating conjunction (because, if, while, etc.).

If you use a coordinating conjunction, place a comma before the conjunction. If you’re using a subordinating conjunction, use a comma only if the subordinate clause comes first. You don’t need a comma if the subordinate clause comes second.

This is a special trip we should get matching tattoos. 

This is a special trip, so we should get matching tattoos. 

Because this is a special trip, we should get matching tattoos. 

We should get matching tattoos because this is a special trip. 

A Checker for Every Sentence
Fix run-on sentences, clarity, tone, and more

Examples of run-on sentences and how to fix them

The light inside is broken the vending machine still works. 
The light inside is broken, but the vending machine still works. 

Red looks too aggressive for the living room walls, let’s try blue. 

Red looks too aggressive for the living room walls; let’s try blue. 

The zombie invasion finally came but I am well prepared so let’s work together. 

The zombie invasion finally came, but I am well prepared. Let’s work together. 

Scarves were popular last season, this season hats are popular. 

Scarves were popular last season. This season, hats are popular. 

The car will start eventually you have to keep trying. 

The car will start eventually; you have to keep trying. 

Types of run-on sentences

What is a fused sentence?

A fused sentence joins two or more clauses without any punctuation.

We met for a date there was no chemistry we won’t meet again. 

What is a comma splice?

Comma splices are when two or more clauses are separated with only a comma and are missing a conjunction.

We met for a date, there was no chemistry, we won’t meet again. 

What is a polysyndeton?

A polysyndeton is a sentence that uses too many conjunctions or more conjunctions than necessary.

We met for a date and there was no chemistry and we won’t meet again. 

Run-on sentences FAQs

What are run-on sentences?

Run-on sentences are a type of grammar mistake that happens when two or more clauses are joined incorrectly.

What are the different kinds of run-on sentences?

There are three types of run-on sentences: A fused sentence is when clauses are joined with no punctuation. A comma splice is when clauses are joined with only a comma (and nothing else), and a polysyndeton is when a sentence uses too many conjunctions or more conjunctions than necessary.

How can you fix a run-on sentence?

You can fix run-on sentences just by adding a semicolon or a conjunction with a comma between the clauses. Alternatively, you can simply split the sentence into two or more separate sentences.

Check my grammar
Sign up to keep going
It’s fast and free. Finish checking your text and create an account to get:
  • Tone and clarity insights
  • Tips on how to engage readers
  • Word choice and inclusive language guidance
Get Grammarly It's free
Already have an account? Log in
Get Grammarly It's free
Already have an account? Log in
Related Articles