An Easy Guide to Using the Comma Right Every Time

If you have been struggling with understanding when to use a comma correctly, this article will serve as your guide to them. We will explain what commas are used for and provide some helpful examples from which you can learn. Understanding correct usage of commas will allow you to express yourself more accurately through writing!

Table of Contents

What is a Comma?

The comma is a punctuation mark that indicates a pause or break between ideas within sentences. It can also be used as a device to indicate separation in lists or to join together two independent clauses.

Types of Commas and Their Use

The Listing Comma (Oxford comma)

What is the listing comma?

A listing comma, or sometimes called a serial comma (Oxford comma), identifies individual items in a list. This can be a list of things within a sentence or two simple words that are linked together (e.g., coffee, tea). The listing comma helps to separate each item clearly so that readers know exactly what is being discussed without confusion.

When should you use a listing comma?

You should use a listing comma when you’re writing out three or more things side by side in your sentence.

Here’s an example: We went to the store to buy eggs, milk, and bread. In this instance, the listing comma helps to distinguish between the three items in question – eggs, milk, and bread – making it easier for readers to follow along with the sequence of items without getting confused.

More common examples of using a listing comma correctly:

I like apples, oranges, and bananas.
We bought groceries, such as bread, butter, and eggs.
The team members included Tom, Jane, and Rick.

‍In these examples above, you can see how the addition of a listing comma after each item helps to clearly define what elements belong together in each list item. As a result, it’s easier for readers to determine which words are being grouped together within each list element. The final example (with Tom, Jane, and Rick) is particularly helpful since it eliminates any possible confusion about whether “Tom” and “Jane” are part of one group or two separate groups within the list structure.

The Joining Comma

The joining comma, also known as the coordinating comma, is used to join two independent clauses (complete sentences) together with a coordinating conjunction (such as “and,” “but,” or “or”).

For example: “I went to the store, and I bought some fruit.”

In this sentence, “I went to the store” and “I bought some fruit” are two independent clauses joined by the coordinating conjunction “and”. The joining comma is used before the conjunction to separate the clauses and make the sentence easier to read.

Commas with But

Commas with ‘But’ in contrasting clauses

When two clauses (or two parts of a sentence) express opposing or contrasting ideas, you often need to separate them with a comma before the coordinating conjunction “but.” For example:

I like chocolate chip cookies, but I don’t like oatmeal raisin cookies.

No commas with ‘but’ independent clauses

If the clause following “but” is dependent then no comma should be used to separate it from the main clause. A dependent clause is one that cannot stand by itself as a complete sentence and expresses incomplete ideas. For example:

I don’t like oatmeal raisin cookies but I do enjoy gingersnaps.

No comma after noun before ‘but’

You should avoid using commas after nouns before connecting them with “but”:

My uncle Tom but not my aunt Sally came to visit.

Commas with And

The first rule is that the word ‘and’ should not be preceded by a comma if the sentence would still make grammatical sense without it.

For example: I like apples, oranges and bananas.

In this case, using a comma before the word ‘and’ would be incorrect because it adds an unnecessary pause in the sentence.

The second rule for using commas with and is that a comma should come before the conjunction if removing it changes or interrupts the meaning of the sentence.

For example: Alex ate breakfast, and then he went to school.

In this case, omitting the comma makes it sound as if Alex ate breakfast while he was at school – not that he ate his breakfast, then subsequently went to school afterwards. Including a comma before ‘and’ here helps signal that two independent clauses are being connected together in order to form one larger sentence, rather than one single thought.

Commas with Or

When “or” is used to join two main clauses in a sentence, a comma should usually come before it. The comma mark is necessary not just for clarity but also to help avoid any confusion that could arise without it. Take this example:

I am going to the shop or I am going to see my friend.

Without a comma, this sentence could lead someone to believe that the shop and friend are linked together as one activity. Adding a comma after “shop” helps disambiguate the meaning:

I am going to the shop, or I am going to see my friend.

If you’re only joining two words (e.g., apples or oranges), then no comma should be added before “or.” Commas should only be included on either side of “or,” when they refer to two separate parts of speech like phrases or clauses connected by “and”/”but”/etc., as these require separation via commas. For example:

These apples green, or these apples red?

A comma would also need to be included if you’re listing more than two items with an “or,” such as:

Green apples, oranges, lemons, or limes?

The Gapping Comma

The gapping comma is a punctuation mark used in a sentence where words have been omitted from the second clause, but are understood to be the same as in the first clause.

For example: “I like coffee, and she tea.” In this sentence, the gapping comma is used to omit the repeated verb “likes” in the second clause, which is understood from the first clause. The sentence could be rewritten as “I like coffee, and she likes tea,” but the gapping comma allows for a more concise and efficient sentence.

Another example: “He can play the guitar, and she the piano.” Here, the gapping comma is used to omit the repeated verb “can play” in the second clause, which is understood from the first clause.

The Bracketing Comma

The bracketing comma, also known as the enclosure comma, is used to set off non-essential or supplementary information within a sentence. This information is usually contained within parentheses, dashes, or commas, and can be removed from the sentence without changing its essential meaning.

For example: “My dog, a golden retriever, loves to play catch.” In this sentence, the bracketing comma is used to set off the non-essential information “a golden retriever.” The sentence would still be grammatically correct without this information: “My dog loves to play catch.”

Another example: “The novel, which was written in the 19th century, is a classic.” Here, the bracketing comma is used to set off the supplementary information “which was written in the 19th century.” The sentence would still be grammatically correct without this information: “The novel is a classic.”

Common Mistakes Involving Commas

Leaving Out Commas When Needed

One of the most common comma errors is missing commas that should have been used. By leaving out a comma between clauses or phrases, you may change the meaning of your sentence entirely or create confusion for your reader.

For example: “I drove to the store but I forgot my wallet” needs a comma after “store” in order to indicate where one clause ends and another begins; if you don’t include it, your reader won’t understand that you’re saying two things (that you drove somewhere, and then something else happened later).

Omitting Commas After Introductory Phrases

Another often-overlooked situation involves leaving out commas after introductory phrases. An introduction usually comes before the main clause in a sentence; adding a comma helps identify this to the reader. For instance, “After dinner I went for a walk” should have a comma after dinner – otherwise, the reader won’t know what happened first!

Placing Commas Between Subjects & Verbs

This is another regular mistake when using commas in sentences – adding too many! Unless there are multiple subjects or verbs being used in tandem in your sentence, there shouldn’t be any need to use a comma to separate them – as it will break up their necessary relation.

The basic rule of thumb here is that unless there’s an extra ‘element’ involved that would require additional context (e.g., “Andy and Jack took turns fishing…), then you don’t need any commas around the subject/verb relationship.

Comma Splices

A final common error involving commas involves overusing them as conjunctions between clauses l incorrectly known as “comma splices”. This mistake occurs when someone attempts to combine two separate independent clauses with just one comma when they actually should connect it with either an appropriate conjunction earlier on within the two clauses — such as “and, but, nor” etc.—or perhaps even by converting them into one longer multi-clause sentence instead (though still including some sort of full stop at some point.).

An example of this would be “Today was hot I stayed inside all day” which should have both at least one conjunction AND/OR either a semicolon OR colon placed between both clauses correctly e.g., “Today was hot; I stayed inside all day”.

Examples of Good Comma Usage

Commas with Dates

Writing Out Just the Month and Year

If you are writing just the month and year when referring to a specific date, no comma should be included. For example, you would write “in April 2020”.

Writing Out the Day, Month, and Year – No Comma Needed

When you include both the day and month as well as the following year in your date reference, no comma is needed. For example, “The deadline for submission was 12 June 2020” does not require any commas after each component of the date.

Writing Out Just the Day and Year or Months Abbreviated

When abbreviating months or including just one component of the full format (such as day or year), it’s important to remember that a comma should always come after that component. So if you wrote “The event will take place on 23 October,” there should be a comma between October and your sentence punctuation such as a period or question mark. Similarly, “We will finish our work in 2021,” must have a comma separating 2021 from your punctuation at the end of your sentence.

Commas with Parentheses

Using a Comma Before a Parenthesis

A comma should be used before the opening parenthesis to indicate that the remainder of the sentence is an aside and not part of the main point of the sentence. For example: “I have several hobbies (baking, acting, sewing), but my favorite is painting.” In this sentence, a comma should precede the parenthesis because baking, acting and sewing are not part of the main point about painting being your favorite hobby.

No Comma After a Parenthesis When It Completes the Sentence

In cases where what is in parentheses completes the larger thought in a sentence or stands as an independent clause within itself, there should not be any punctuation after it. For example: “I love going out for coffee (especially espresso).” In this sentence, “especially espresso” completes “I love going out for coffee” so there is no need for any additional punctuation at its close.

Using a Comma After a Parenthesis

When using parentheses to add further information on something another person has said or written, use a comma after both sides of parentheses; however, if you are using parentheses that contain words that are part of your original thought then don’t use any punctuation outside them. For example: “My brother is always eating chocolate cake (he’s really addicted to sugar).”

Commas with Question Tags

When a question tag is added to the end of a statement, there must be a comma before the question tag. This applies even if the question tag comes after an exclamation point; in this case, use a comma both before and after the question tag:

He’s amazing, isn’t he?
She works hard, doesn’t she?
They’re going on vacation next week, aren’t they?
He’s already gone, hasn’t he?!

Commas with As Well As

When using “as well as” in your sentence, you should place a comma before and after it. This includes when it appears in lists or is part of an introductory phrase. For example: