Do You Need a Comma Before or After a Conjunction?

Comma rules are one of the most complicated elements of English grammar, especially when you combine them with other grammar rules like conjunctions.

So, do you need to use a comma after a conjunction? What about before a conjunction?

You need to use a comma before or after a conjunction in some sentences, but not in others. Whether or not you need a comma depends on the specific type of conjunction you’re dealing with.

Read on to learn how to use commas correctly with conjunctions.

What Is a Conjunction?

A conjunction is a word that connects other words so you can create more complicated sentences.

For example, if you have two short sentences like “I like grapes” and “She likes cheese,” you might connect them with the conjunction and to form the sentence “I like grapes, and she likes cheese.”

There are three common types of conjunctions: subordinating conjunctions, coordinating conjunctions, and correlative conjunctions. Whether or not you need to use a comma before a conjunction depends on what kind of conjunction you’re working with.

Let’s look at the rules for commas with each type of conjunction.

Commas with Subordinating Conjunctions

A subordinating conjunction connects a subordinate clause, also known as a dependent clause, to the rest of the sentence. Because a dependent clause can’t stand on its own, it needs to be connected to an independent clause to form a complete sentence.

Common subordinating conjunctions include although, as, because, before, despite, since, unless, until, and when.

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When the subordinate clause comes before the independent clause, you don’t need to use a comma directly after the conjunction, but you should use a comma to separate the two clauses.

Here are some examples of sentences where you need a comma between the subordinate clause and the independent clause:

• After eating a meal, you should wash your own dishes.

• Despite having plenty of money, he refuses to buy anything for himself.

• Until the bell rings, we have to stay in our seats.

When the independent clause comes first in the sentence, whether or not you need a comma depends on how important the subordinate clause is.

If the subordinate clause is crucial for the reader to understand the sentence, you shouldn’t use a comma to separate the two clauses. Consider the following examples:

• You should wash your own dishes after eating a meal.

• We have to stay in our seats until the bell rings.

However, you should use a comma if the subordinate clause is incidental to the independent clause. The comma helps set the clause apart from the rest of the sentence.

• He refuses to buy anything for himself, despite having plenty of money.

Do You Need Commas for Coordinating Conjunctions?

Coordinating conjunctions are used to join grammatically similar elements (two nouns, two verbs, two modifiers, two independent clauses, etc.). The most frequently used coordinating conjunctions are and, or, nor, so, but, for, and yet.

Coordinating Conjunctions with Two Independent Clauses

When a coordinating conjunction is used to separate independent clauses, you should use a comma before the coordinating conjunction.

Here are some examples of coordinating conjunctions that connect independent clauses:

• It rained for twenty days in a row, so it was no surprise when the river burst its banks.

• I like cheese, but I don’t like crackers.

• You can finish your homework tonight, or you can wake up early to do it tomorrow.

Coordinating Conjunctions with Simple Words and Phrases

You don’t need to use a comma if the coordinating conjunction is used to connect simple words and phrases rather than independent clauses.

The Oxford comma, which comes before the coordinating conjunction at the end of a list, is optional. You can decide whether to include an Oxford comma when you write a list.

Here are some examples of coordinating conjunctions that connect words and phrases. In the first example, the comma after Tom is an Oxford comma, which is an optional stylistic choice:

• John, Tom, and Mary went to the store together.

• Do you want strawberries or blueberries on your pancake?

• My father is harsh but fair.

Do You Need Commas for Correlative Conjunctions?

Finally, correlative conjunctions, also known as paired conjunctions, are used in pairs to structure a sentence in a specific way. Some examples include both/and, whether/or, either/or, and neither/nor.

You usually don’t need to use any commas with correlative conjunctions.

Here are some examples of sentences with correlative conjunctions:

• Neither Kathy nor Sammy are going to the party tomorrow.

• I think I’ll buy either chocolate ice cream or a chocolate chip cookie.

• Whether you like it or not, you’re going to have to learn English grammar.

How ProWritingAid Can Help You Use Commas with Conjunctions

If you’re not sure you’re using commas before and after conjunctions correctly, you can run your writing through ProWritingAid. Our free grammar checker will highlight any punctuation and spelling errors and help you fix them with a simple click.

Good luck, and happy writing!