Should a Comma Go Before or After So?
  • 3-minute read
  • 30th June 2023

Should a Comma Go Before or After So?

Commas are small but mighty pieces of punctuation. Where they’re placed can impact the meaning of an entire sentence.

When using the word so, whether you place a comma before it or after it (or don’t use one at all) depends on the sentence. Making sure you place it in the right spot can make all the difference. Let’s see how.

Placing a Comma Before So

So is a versatile word. It can be a conjunction (both coordinating and subordinating), an adverb, or an introductory word to a parenthetical expression.

When so takes the form of a coordinating conjunction, it’s used to connect two independent clauses. These are clauses that can stand on their own as complete sentences. For example:

The roses are in bloom.

The roses smell lovely.

To connect these two independent clauses, we’d use a coordinating conjunction: for, and, nor, but, or, yet, and so (also known as FANBOYS):

The roses are in bloom, and they smell lovely.

When so is used as a coordinating conjunction, you need to place a comma before it (as with other FANBOYS clauses):

Our house was flooded, so we stayed at a hotel.

The sun was setting, so the backdrop was beautiful.

Placing a Comma After So

When so is used to introduce a parenthetical expression, you’ll need to place a comma after it. A parenthetical expression is a dependent clause inserted into the middle of a sentence to provide more information. For example:

I have some errands to run so, if you stop by, I might not be home.

The movie starts at 5:00 so, if you’re getting popcorn, you should get there early.

Sometimes, so is used at the beginning of a sentence. In this case, you should also place a comma after it:

So, what’s for dinner?

So, how have you been?

So, (see what we did there?) is there ever a time when you don’t need a comma with so? Let’s see.

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When Not to Use a Comma with So

When so acts as a subordinating conjunction, you shouldn’t use a comma. As we learned earlier, coordinating conjunctions connect two independent clauses. A subordinating conjunction, therefore, connects an independent clause with a dependent clause.

A dependent clause adds information to the independent clause that’s essential for the meaning. It’s dependent on the independent clause for it to make sense. When so is used to connect them, it’s to show a cause-and-effect relationship. For example:

I left work early so I wouldn’t hit traffic.

We stopped at the store so we could pick up ice cream.

A handy way to determine if so is acting as a subordinating conjunction is to try placing that after it. If it works, then it’s subordinating and does not need a comma:

I left work early so that I wouldn’t hit traffic.

We stopped at the store so that we could pick up ice cream.


So, did this post help you out? (Okay, we’ll stop now). Hopefully, you now feel confident when deciding where to place a comma with the word so.

If you’d like an expert to check your work, though, send it our way. Our editors will make sure your grammar, spelling, punctuation, and word choice are perfect. We’ll even edit your first 500 words for free!

Frequently Asked Questions

What are FANBOYS?

FANBOYS stands for the coordinating conjunctions for, and, nor, but, or, yet, and so. These words are used to connect independent clauses.

Can you use so without a comma?

When using so to connect an independent clause with a dependent clause, you shouldn’t use a comma: I’m leaving now so I can stop for coffee on the way.

Comments (2)
George Joshua
28th August 2023 at 21:26
The "that" test for distinguishing between the use of "so" as a cordinator and subordinator clears my confusion on the use of "so". Thanks for this.
Mohamed Osman
30th August 2023 at 03:39
Your explanation is perfectly clear so, I don't have a comment.

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