Commas with Independent Clauses

The Rule*:

Place a comma between independent clauses when they are joined by a coordinating conjunction.

No comma is used if the conjunction is not joining independent clauses.

Do not put a comma between independent clauses without a coordinating conjunction (called a comma splice). 

*While I use the term “rule,” please know that these are more like guidelines, and once you know and understand this rule, you may chose to break it to create an intentional effect. 

Terms to Know:

Independent Clause: A clause contains both a subject and a verb, and an independent clause can stand on its own.

Coordinating Conjunction: A word that joins words, phrases, and clauses.

For, and, nor, but, or, yet, so

A Note on So:

So does not always take a comma. When it means therefore, a comma is used; when it means in order that, a comma is not used.

Examples:

I took my car through the car wash yesterday, but it got dirty the very next day.

• There are two independent clauses in that sentence: I took my car through the wash yesterday. It got dirty the very next day. Since the clauses are joined with the conjunction but, a comma is placed between the clauses.

She sang very well and got the part.

• There is only one independent clause in that sentence: She sang very well. Got the part is not an independent clause since it doesn’t contain a subject and can’t stand on its own.

I was sick that day, so I had to make up the test.

• There are two independent clauses and so means therefore in this sentence.

She whispered her plans so no one else would hear.

• There are two independent clauses and so means in order that in this sentence.

I took my car through the wash yesterday, it got dirty the very next day.

• The comma is incorrect here since there isn’t a coordinating conjunction between the two independent clauses.

Practice:

1. He left the scene of the accident and tried to forget what happened.
2. My mom loves the outdoors but my dad prefers to sit inside and read.
3. He stood in the shadow so I couldn’t see his face clearly.
4. Tess can risk everything on the next question or she could take the money now.
5. Because I studied and feel prepared, I will do well on the test but I am not sure about the essay portion.
6. The show was OK but didn’t deliver on its promise.
7. I have been pumping all day so I hope I got enough milk.
8. He keeps kicking off his blanket and I have to pick it back up.
9. After the town hall meeting, we all went and got ice cream and stood in line forever.
10. I hope you’re getting it but if not, practice makes perfect.

Answers:

1. He left the scene of the accident (no comma) and tried to forget what happened.
2. My mom loves the outdoors, but my dad prefers to sit inside and read.
3. He stood in the shadow (no comma) so I couldn’t see his face clearly.
4. Tess can risk everything on the next question, or she could take the money now.
5. Because I studied and feel prepared, I will do well on the test, but I am not sure about the essay portion.
6. The show was OK (no comma) but didn’t deliver on its promise.
7. I have been pumping all day, so I hope I got enough milk.
8. He keeps kicking off his blanket, and I have to pick it back up.
9. After the town hall meeting, we all went and got ice cream (no comma) and stood in line forever.
10. I hope you’re getting it, but if not, practice makes perfect.