Comma Splice—What It Is and How to Fix It

I recently saw a post educating on a comma splice. Since my website blog offers information, advice, and tips on grammar mechanics, this is a good topic for my next post. As a professional proofreader, I have noticed quite a few examples similar to these:

1)    There is a cane spider on the windowsill, it is enormous.

2)    The dog jumped over the fence and sped down the road, it must have been going 25 miles an hour.

The common denominator in examples 1 and 2 is two complete sentences or thoughts containing a subject and a verb joined by a comma. From here on, you can refer to these sentences as independent clauses. Linking the independent clauses with a comma is incorrect; this is where the term comma splice comes into play. In examples 1 and 2, the comma incorrectly splices two complete sentences or independent clauses, simultaneously creating a run-on sentence. Beware of this!

 Although you should not use a comma as punctuation to link two complete sentences, the good news is that you have different punctuation options for correcting this. You can use a period, semicolon, or, under certain circumstances, a colon, or my personal favorite, an em dash as follows:

1)  There is a cane spider on the windowsill. It is enormous.

There is a cane spider on the windowsill; it is enormous.

There is a cane spider on the windowsill: it is enormous.

There is a cane spider on the windowsill—it is enormous.

2)  The dog jumped over the fence and sped down the road. It must have been going 25 miles an hour.

The dog jumped over the fence and sped down the road; it must have been going 25 miles an hour.

The dog jumped over the fence and sped down the road: it must have been going 25 miles an hour.

The dog jumped over the fence and sped down the road—it must have been going 25 miles an hour.

Note: You should only use a colon or em dash to correct a comma splice when the second independent clause clarifies or elaborates on the first clause. If neither applies, using a period or semicolon is best practice.

Misusing punctuation can impact your message to your audience, so just be mindful. Follow the rules, and your message will be clear. Above all, have fun exploring various types of punctuation. If used correctly, punctuation can add flair, pizazz, and interest to your prose. To assist with punctuation rules, I highly recommend this resource—The Best Punctuation Book, Period by June Casagrande.

Happy Writing and Punctuating!