The FANBOYS Comma Rule

When I say “FANBOYS,” I don’t mean the ones who geek out about cult TV shows; I mean the acronym.

FANBOYS is how you remember the coordinating conjunctions you’ll have to watch for when editing comma usage:

  • For
  • And
  • Nor
  • But
  • Or
  • Yet
  • So

Related: Don’t Just Add a Comma Where You’d Normally Pause

Conjunction Junction, What’s Your FUNction?

When these conjunctions are used to combine complete sentences, they should always follow a comma.

I slept all day [comma] and I wrote all night.

There are instances in which they don’t get a comma, though. Namely, when they are simply “hooking up” phrases that don’t qualify as complete or independent with both subject and verb.

I use both pen [no comma] and paper when I write.

So What’s a Comma Splice?

The term “comma splice” refers to the error in which a comma alone separates two complete or independent clauses or phrases. Notice there’s no conjunction:

I slept all day [comma] [missing conjunction] I wrote all night.

The conjunction is necessary for the comma to be used. Therefore, in the above example, the comma is incorrectly “splicing” the sentence.

Sometimes, I will call the error in which a comma is incorrectly used with a conjunction when the phrases are dependent or incomplete (see below), but this is not a true comma splice. I just don’t know what to call it.

If YOU do, comment below and win a featured spot right here!


I use both pen [incorrect comma] and paper when I write.

Since “paper when I write” cannot stand alone, the conjunction does not need its helper comma.

Related: Up Your Comma Game by Learning These 3 Essential Rules

How to Fix Comma Splices

If you look at the above errors, you’ll notice that the key is in identifying complete sentences and using FANBOYS correctly. To fix the above errors, either add the right conjunction in the right place

I slept all day [comma] [insert conjunction "and"] I wrote all night.

or use a semicolon instead.

I slept all day [semicolon] [no conjunction] I wrote all night.

Be sure to remove commas with conjunctions that are not joining complete phrases.

I use both pen [no comma] [insert conjunction 'and'] paper when I write.

Commonly Confused Commas

Because they are not FANBOYS coordinating conjunctions, the following words do not pair with commas:

  • Because
  • Since
  • As

These often imply causation, which would be subordinate or dependent on the preceding phrase despite its ability to stand alone. View a full list of subordinating conjunctions here.

Happy coordinating!

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