Fixing Run-on Sentences

Before you can fix a run-on sentence, you’ll need to identify the problem. When you write and revise, carefully look at each part of every sentence. Are the parts independent clauses, or are they dependent clauses or phrases? Remember, only independent clauses can stand on their own. This also means they have to stand on their own; they can’t run together without correct punctuation.

There are five ways you can fix a run-on sentence or comma splice:

1. Change the comma in the comma splice to a semicolon (or add a semicolon between the independent clauses).
2. Change the comma in the comma splice to a colon, but only if the two clauses are very closely related and the second one seems to be explaining or clarifying the first.
3. Add a coordinating conjunction (FANBOYS) after the comma in the comma splice.
4. Change the comma to a period and separate the two independent clauses into two separate sentences.
5. Rewrite the sentence entirely so the run-on sentence is no longer a problem.

Fixing a Comma Splice

Here is an example of a sentence with a comma splice:

• Jill has been waiting for years for this doctor’s appointment, it’s very frustrating to have it postponed.

Now let’s look at how we can revise the comma splice using the techniques learned above:

1. Changing to a semicolon
   1. Jill has been waiting for years for this doctor’s appointment; it’s very frustrating to have it postponed.
2. Changing to a colon
   1. Jill has been waiting for years for this doctor’s appointment: it’s very frustrating to have it postponed.
3. Adding a coordinating conjunction
   1. Jill has been waiting for years for this doctor’s appointment, so it’s very frustrating to have it postponed.
4. Changing to a period and separating into two sentences
   1. Jill has been waiting for years for this doctor’s appointment. It’s very frustrating to have it postponed.
5. Rewriting the sentence
   1. Jill has been waiting for years for this doctor’s appointment, making it very frustrating to have it postponed.

Let’s take a look at a few other run-on sentences and their revisions:

• Most of the hours I’ve earned toward my associate’s degree do not transfer, however, I do have at least some hours the university will accept.

This is a comma splice. The adverbial conjunction “however” is being treated like a coordinating conjunction (remember, FANBOYS). There are two easy fixes to this problem. The first is to turn the comma before “however” into a period:

• Most of the hours I’ve earned toward my associate’s degree do not transfer. However, I do have at least some hours the university will accept.

If this feels like too hard of a stop between ideas, you can change the comma into a semicolon instead:

• Most of the hours I’ve earned toward my associate’s degree do not transfer; however, I do have at least some hours the university will accept.

Let’s take a look at another sentence.

• The opposite is true of stronger types of stainless steel they tend to be more susceptible to rust.

This second sentence is a run-on as well. “The opposite is true of stronger types of stainless steel” and “they tend to be more susceptible to rust” are both independent clauses. Since the two clauses are very closely related, and the second clarifies the information provided in the first, the best solution is to insert a colon between the two clauses (although a semicolon is grammatically correct as well):

• The opposite is true of stronger types of stainless steel: they tend to be more susceptible to rust.

Let’s try another one.

• Some people were highly educated professionals, others were from small villages in underdeveloped countries.

In this last example, once again, we have two independent clauses. The two clauses provide contrasting information. Adding a conjunction could help the reader move from one kind of information to another. However, you may want that sharp contrast. Here are two revision options:

• Some people were highly educated professionals, while others were from small villages in underdeveloped countries.
• Some people were highly educated professionals. Others were from small villages in underdeveloped countries.