Strategies for Eliminating Run-On Sentences

A common misconception in academic writing is that complex and long sentences are preferable to ones that are simple and short. While long sentences certainly can demonstrate an author’s literary prowess, not all long sentences are created equally. In fact, when constructed poorly, a long sentence can greatly inhibit readers’ understanding of a manuscript. In the context of an academic manuscript, it is important to be mindful of grammatical conventions and be as concise as possible.

Run-on sentences occur when two or more independent clauses are joined without the appropriate punctuation and/or conjunctions. Not all long sentences are run-on sentences, and not all run-on sentences are very long. Often, run-on sentences occur because an author is trying to connect too many ideas in one sentence, and in the process they accidentally break some grammar rules. To better understand how a run-on sentence occurs, let’s break this down grammatically.

How to identify run-on sentences

An independent clause contains a subject and a verb, and it expresses a complete thought. An independent clause can stand on its own, meaning that it can be a full sentence exactly how it is. Here is an example of an independent clause:


This example contains a subject (“I”) and a verb (“went”). It expresses a complete thought because the reader knows who went to the store and what they did.

In contrast, a dependent clause is not a full sentence, and it cannot stand on its own. For example:


Although this dependent clause contains both a subject and a verb, it is not a full sentence, nor does it express a complete thought. The reader is left to wonder, what happened because you went to the store yesterday? An independent clause is required to finish this sentence. We will show an example of this later on in the article.

Let’s take a look at an example of a run-on sentence:

I went to the store yesterday, I have everything I need to make dinner.

In this example, “I went to the store yesterday,” and “I have everything I need to make dinner” are both independent clauses, and they are inappropriately joined by a comma. This particular form of a run-on sentence is probably the most common, and it is called a “comma splice.”

How to correct run-on sentences

1. The simplest way to correct a run-on sentence is to separate it into two or more sentences using a period.

I went to the store yesterday. I have everything I need to make dinner.

Although this method can sometimes be choppy, it conveys information effectively and in a way that is grammatically correct.

2. A semicolon is another option. Use of a semicolon requires that the clauses surrounding it are both independent, meaning that they are full sentences. A semicolon can be used in two ways, with or without a “connector.”

I went to the store yesterday; therefore, I have everything I need to make dinner.

This is an example of using a semicolon and a connector to correct a run-on sentence. In this case, “therefore” serves as the connector to explain the relationship between the two clauses. A few examples of connectors are words or phrases such as “however,” “in addition,” and “moreover.”

The connector can also be omitted in many cases. Again, this may render the sentence a bit more choppy, but it will still be grammatically correct.

I went to the store yesterday; I have everything I need to make dinner.

3. You can also add a comma followed by a coordinating conjunction. The full list of coordinating conjunctions is as follows: for, and, nor, but, or, yet, so. If you have trouble remembering the coordinating conjunctions, you can use the mnemonic device “FANBOYS”.

I went to the store yesterday, so I have everything I need to make dinner.

4. A more complex way of correcting a run-on involves turning one clause into a dependent clause by using a subordinating conjunction. Examples of subordinating conjunctions include “because,” “unless,” “although,” “if”, and “so that.” There are too many subordinating conjunctions to count, but as a general rule you can identify whether something is a subordinating conjunction because it will make one idea rely on the other, or it will indicate a relationship of time, condition, cause, contrast, or purpose. Connecting a dependent clause and an independent clause will not result in a run-on sentence.

Because I went to the store yesterday, I have everything I need to make dinner tonight

This sentence contains a dependent clause (“Because I went to the store yesterday”) and an independent clause “I have everything that a need to make dinner tonight.” These two dependent clauses are appropriately joined by a comma. The subordinating conjunction “because” indicates that “having everything to make dinner tonight” is reliant on having “been to the store yesterday.”

When using this method, please note that in some cases, the subordinating conjunction method may require you to alter the tense of the verb or other parts of the sentence. For example,

I went to the store yesterday so that I would have everything I need to make dinner tonight.

In academic writing, clarity and conciseness are paramount, and run-on sentences often hinder readability. By employing the above strategies, you can more effectively convey your ideas, ensure that the reader follows the intended meaning without unnecessary confusion, and boost the impact of your writing.