Commas and Conjunctions – Ultimate Guide (with Worksheet)

Commas are the most common punctuation mark you can use in your writing. They indicate a brief pause and provide sentence structure and clarity to your reader.

Conjunctions are linking words, the most common parts of speech to create sentence fluency and add detail to text and speech.

Together they work to combine grammatically correct sentences and add sophistication to your material. But, what rules of grammar concerning conjunctions should you know? For example, do commas belong before conjunctions? Or do commas belong after conjunctions?

I’ve broken down the use of both the usage of commas and conjunctions below so you understand their use and can more easily understand conjunction comma rules and apply it to your own writing.

What are Conjunctions?

Conjunctions are words that link together other words, clauses, or phrases in a sentence. They allow you to form complex, compound sentences and avoid the choppy interruption of simple clause structure. When you join together phrases and clauses, you want to make sure your sentences have a parallel, or same structure.

Conjunction examples:

• She worked efficiently and quickly to complete the job.
• After school, we need to get home so I can make dinner, and my children must complete their weekly laundry.

Types of Conjunctions

There is more than one type of conjunction, and not all need a comma to be used correctly. Make sure you understand the difference between different conjunctions so you can recognize their use and properly place them in your own writing.

Knowing how to combine clauses and phrases and use punctuation correctly helps your readers take your messages seriously and is especially important when you need to communicate important information for work.

Take a quick look at this simple guide to conjunctions so you better recognize their use. 

Coordinating Conjunctions

A coordinating conjunction is a popular way to combine words, phrases, and clauses in a sentence. These include the following words:

• For
• And
• Not
• But
• Or
• Yet
• So

For example:

• She’s heading to the beach tomorrow, not the river.
• I want to go out for dessert, but I’m watching my diet.
• It isn’t hard to make a decision, yet here I am still contemplating my choices.

Correlative Conjunctions

Correlative conjunctions are pairs of conjunctions that work together in the same sentence to join phrases and clauses. These include the following pairs:

• either/or
• neither/nor
• both/and
• not only/but
• whether/or

For example:

• I am traveling with both my best friend and my favorite dog.
• The movie was not only sold out, but our favorite ice cream store was closed.
• You will neither pass this class nor participate in the play due to poor choices.

Subordinating Conjunctions

Subordinating conjunctions join together an independent and dependent clause and are made up of a word or a series of words. They are the more difficult conjunctions to recognize since they occasionally  include adverbs functioning as a conjunction.

They represent a relationship between the two clauses. Here is a list of common subordinating conjunctions you can use to help create more sophisticated sentences. 

• after
• although
• as
• as if
• as long as
• as much as
• as soon as
• as though
• because
• before
• by the time
• even if
• even though
• if
• in order that
• in case
• in the event that
• lest
• now that
• once
• only
• only if
• provided that
• since
• so
• supposing
• that
• than
• though
• till
• unless
• until
• when
• whenever
• where
• whereas
• wherever
• whether or not
• while

For example:

• I’ll be staying late at school unless a note excuses me.
• I can be a part of the drill team only if my grades improve.

A subordinating conjunction doesn’t have to be placed in the middle of a sentence either. It only has to be part of the dependent clause.

• Before the alarm rings, make sure your work is turned in.

When to Use Commas with Conjunctions

There are a few rules to remember concerning when conjunctions need commas. These are specific to rules for comma use and are not new or specific only to conjunctions. If you are already familiar with correct comma placement, this will be a simple review.

When (and When Not) to Use Commas with Coordinating Conjunctions

There are only two key rules pertaining to coordinating conjunctions that need to be remembered. Both are specific to comma rules and are easy to understand.

Rule #1: Place a comma before the conjunction when linking two or more independent clauses

When using coordinating conjunctions to link two or more independent clauses, you must use commas  before conjunctions to separate them.

For example:

• The lesson wasn’t challenging to follow, and I was confused about why my classmates were struggling.

Rule #2: DO NOT use a comma with a conjunction when linking something other than two independent clauses.

It’s important to remember that not all coordinating conjunctions link together independent clauses. If the conjunction connects something other than two independent clauses, it doesn’t need a comma.

Coordinating conjunctions also join compound subjects, verbs, prepositional phrases, and clauses. Not all require the use of a comma. Avoid commas in the following scenarios:

When to Use Commas with Correlative Conjunctions

Correlative conjunctions follow the same rules as coordinating conjunctions. If two or more independent clauses are joined together, you must place a comma before the conjunction that links the clauses.

For example:

• Either you will pass this class, or you will struggle with this skill and need to retake it.
• Not only will I be bringing the dogs with me on vacation, but I also plan on letting them go camping with us later this summer.

When to Use Commas with Subordinating Conjunctions

There is only one rule concerning subordinating conjunctions and commas: subordinating conjunctions DO NOT require commas.

Since a subordinating conjunction connects a dependent clause to an independent clause, no commas are needed. Dependent or subordinate clauses cannot stand by themselves and therefore do not need a comma to indicate possible independence. One of the most common comma mistakes it to use them with a subordinate clause, but remember you don’t need to. 

For example:

• We didn’t get our work done because the power went out last night.
• I’ll be there as soon as I get this trailer loaded and tire pressure checked.

Let’s Review

There are three types of conjunctions, but not all need the addition of a comma to be used grammatically correctly. Coordinating and correlative conjunctions require the use of a comma when two independent clauses are joined together, but if a compound subject or verb is joined, a comma is not needed. A comma is also not needed when joining prepositional phrases or subordinate clauses.

Subordinating conjunctions never require a comma, either.