Commas serve many functions, joining two complete sentences is not one of them.
Did you spot the error in the last sentence? I didn’t follow my own advice and spliced together two independent clauses with a comma. (An independent clause is a group of words that can stand alone as a sentence.)
Let’s review how you can avoid the same type of error in your business writing.
How can I fix a comma splice?
A comma splice occurs when a comma is used to join two sentences. You can fix this common error in one of three ways:
1. Insert a coordinating conjunction (and, but, or, nor, for, yet, so) after the comma. Choose this option to create a compound sentence.
Commas serve many functions, but joining two complete sentences is not one of them.
A comma and a conjunction must work in tandem to connect two complete sentences. A conjunction without a comma is a punctuation error. If you leave out both the comma and the conjunction, you form a run-on.
2. Replace the comma with a period and capitalize the new sentence. Choose this option when you want to separate the two sentences.
Commas serve many functions. Joining two complete sentences is not one of them.
3. Replace the comma with a semicolon. A semicolon creates a softer break than a period but a stronger pause than a comma. Semicolons work best when the ideas in the two sentences are closely related, with one naturally leading into the other.
Commas serve many functions; joining two complete sentences is not one of them.
Where do comma splices often occur?
Watch for comma splices in between short, simple sentences that share related ideas.
Jan sent the memo, I signed it.
Even though these clauses contain few words, each forms a complete thought. A comma alone is not strong enough to join the clauses.
Jan sent the memo, and I signed it.
Comma splices also appear when writers incorrectly treat conjunctive adverbs—like however—as coordinating conjunctions.
I was ready to give my presentation, however it was cancelled at the last minute.
If you use a conjunctive adverb in between independent clauses, insert a semicolon before the adverb and a comma after it.
I was ready to give my presentation; however, it was cancelled at the last minute.
Conjunctive adverbs are transition words that you can imagine a professor saying:
accordingly, also, besides, certainly, consequently, finally, further, furthermore, however, incidentally, indeed, instead, likewise, meanwhile, moreover, namely, nevertheless, next, nonetheless, now, otherwise, similarly, still, then, therefore, thus, undoubtedly