What is a run-on sentence?

A run-on sentence is when two independent clauses are joined without the proper punctuation.

There are two kinds of run-ons: Fused sentences are run-on sentences where two independent clauses are joined in one sentence without any punctuation (except the period). Comma splices are run-ons where there is a comma separating the two independent clauses.

Why do run-ons happen? Usually a run-on occurs because the writer intuitively knows the two ideas belong together. Often the second independent clause comments on the idea in the first clause.

Because run-ons aren’t written properly, the reader can’t recognize where one complete thought begins and one ends.

Here are two easy ways to spot run-ons. Use the “I realize” method for testing whether or not each section of your sentence is a fragment or a complete sentence/independent clause. If you suspect a sentence might be a run-on, try placing an “imaginary period” between the sections. If this works, then your sentence is a run-on.

There are four ways to fix them. One of the easiest ways to fix a run-on sentence is to turn it into two individual sentences. (It already is two complete sentences or independent clauses, so all it really needs is a period and a capital letter!)

A second way to fix a run-on sentence is to combine the two independent clauses with a comma and a coordinating conjunction.

A third way to fix a run-on sentence is by placing a semicolon between the two independent clauses to properly combine them in one sentence.

A fourth way to correct a run-on sentence is by turning one of the independent clauses into a dependent clause.

The rain was loud the sky was dark. Is this a run-on? If so, what kind is it?

The rain was loud the sky was dark. This is an example of a fused sentence.

The rain was loud, the sky was dark. What kind of run-on is this?

The rain was loud, the sky was dark. This is an example of a comma splice.

The rain was loud. The sky was dark. Here the run-on was fixed by turning it into two separate sentences.

The rain was loud, and the sky was dark. Here the run-on was fixed by adding a comma and the coordinating conjunction “and” between the two independent clauses.

The rain was loud; the sky was dark. Here the run-on was fixed by inserting a semicolon between the two independent clauses.

When the sky was dark, the rain was loud. Here the run-on was fixed by turning one of the independent clauses into a dependent clause by using the subordinating conjunction “when.”

What else matters? When you are choosing which of the four methods you want to use to fix a run-on sentence you’ve discovered in your work, be sure to always take the time to consider the meaning and the emphasis you place with each correcting option.