Commas can be a particularly tricky punctuation mark. There are some cases where you know you should use a comma – such as when separating items in a list – but there are other times when you might be unsure whether or not a comma is needed.
While there’s some degree of flexibility in how commas are used, it’s important to have a clear grasp of the rules.
Seven Places Where You SHOULD Use Commas
Rule #1: Use Commas to Separate Items in a List
- This probably the first use of commas you learned in school: separating items in a list of three or more things.
- Here’s an example:
- The cake mix requires flour, sugar, eggs, and butter.
Note that some style guides would not add the comma after the word “eggs”. For more on this, see Rule #8.
Rule #2: Use a Comma After an Introductory Word or Phrase
- When a word or phrase forms an introduction to a sentence, you should follow it with a comma, as recommended by Purdue OWL.
- Here are some examples:
- However, she didn’t love him back.
- On the other hand, it might be best to wait until next week.
Rule #3: Use a Comma Before a Quotation
- You should always put a comma immediately before a quotation:
- He said, “It’s warm today.”
- John Smith told us, “You can’t come in after ten o’clock.”
Rule #4: Use a Comma to Separate a Dependent Clause That Comes BEFORE the Independent Clause
- A dependent clause, or subordinate clause, is one that can’t stand alone as a whole sentence. It should be separated from the independent clause that follows it using a comma:
- If you can’t make it, please call me.
- After the race, John was exhausted.
- However, it’s normally not necessary to use a comma if the independent clause comes first:
- Please call me if you can’t make it.
- John was exhausted after the race.
- For more on this, plus an example of an instance where a comma is required after the independent clause, take a look at Subordinate Clauses and Commas.
Rule #5: Use a Comma to Join Two Long Independent Clauses
- Normally, you should put a comma between two complete sentences that are joined with a coordinating conjunction (and, or, but, for, nor, so, yet) that creates a single sentence with two independent clauses:
- Sue didn’t know whether she had enough money in her account to pay for the groceries, so she went to an ATM to check her balance.
- John was determined to get the unicorn slime his daughter wanted, but all the shops had sold out.
- You don’t need a comma if both the independent clauses are relatively short and similar in meaning:
- Sue went to the shops and John went home.
Rule #6: Use Commas to Set Off an Nonessential Element within a Sentence
- Sometimes, you might want to include extra information within a sentence that isn’t essential to its meaning. You should set this information off using a comma before and a comma after it:
- John went for a jog, which took half an hour, before having a long hot shower.
- Writing a book, if I haven’t put you off already, is one of the most rewarding things you can do.
- The sections in bold could be removed from the sentences completely and it would still make perfectly good sense.
You could also use dashes in this context:
- John went for a jog – which took half an hour – before having a long hot shower.
Dashes are useful if you want to imply a longer pause, or draw more attention to the nonessential element of the sentence.
They’re also useful if you have several other commas in the sentence, to help avoid confusion.
Rule #7: Use Commas to Separate Coordinate Adjectives
When you’re describing something with two or more adjectives, you can use a comma between them if those adjectives are coordinating. (They’re coordinating if you could place “and” between them.) You shouldn’t put a comma after the final adjective.
- For example:
- He’s a cheerful, kind boy.
- A comma is used here, because it would also make sense to say, “He’s a cheerful and kind boy”.
- There’s a blue bath towel on your bed.
Here, “bath” is acting as an adjective to modify “towel”, but it’s not coordinate with “blue”. It wouldn’t make sense to say, “There’s a blue and bath towel,” so no comma is used.
For more on coordinate and non-coordinate adjectives, check out this post.
One Place When You CAN Use a Comma
While commas are normally either required or not required, there’s one key instance when you can choose whether or not to use a comma – and either option is equally correct.
Rule #8: If You Use a Serial Comma, Use it Consistently
Improve Your Writing
The comma is a much misused and often over used piece of punctuation. The complexity of its usage stems primarily from the fact that there are several different situations in which the comma is the correct piece of punctuation to use. The trick is to identify those situations so as not to use the comma in places where it really should not be.
The following are some of the situations in which a comma should be used:
1. To separate the elements in a list of three or more items.
The potion included gobstoppers, chewing gum, bran flakes and coleslaw.
There appears to be some debate about whether or not to include a comma to separate the last two items in the series. Personally I was taught to omit the comma before the final 'and' unless there is a danger that the last two items in the series will merge and become indistinguishable without the comma.
His favourite puddings were ice apple pie, rhubarb crumble, and jelly and ice cream.
In this sentence it is acceptable to use a comma after the word crumble in order to indicate that the jelly and ice cream is considered as a single item in the series. This is called the Oxford comma. There are occasions where it is definitely needed in order to avoid unnecessary confusion. In the sentence below, the inclusion of the Oxford comma would have avoided some confusion.
I dedicate this work to my parents, Marie Smith and God.
2. Before certain conjunctions.
A comma should be used before these conjunctions: and, but, for, nor, yet, or, so to separate two independent clauses. They are called co-ordinating conjunctions.
She was a fantastic cook, but she would never be as good as her mother-in-law.
He hated his neighbours, so he never invited them round.
A common mistake is to put the comma after the conjunction.
It is not usually necessary or indeed correct to use a comma with the conjunction 'because'.
We all had to move to higher ground because the floodwaters were rising quickly.
She really didn't feel hungry because she had already eaten a hearty lunch.
However, there are occasions when a 'because clause' needs to be set off with a comma in order to avoid any confusion of meaning.
I knew she would not be hungry, because my sister works in a restaurant and had seen her eating a huge meal earlier in the day.
In this example the reason for the person in question not being hungry is nothing to do with the sister's working in a restaurant as might be indicated if the comma were omitted.
3. To separate introductory elements in a sentence.
Use a comma to separate introductory elements in a sentence from the main part of that sentence.
- Given the appalling weather conditions, Michael was lucky to survive the storm.
- As the night drew to a close, the clubbers wandered home.
- Having mastered the use of the colon, you can make it work for you in your writing.
If the introductory element of the sentence is very short, it is permissible to omit the comma. If the introductory phrase is more than about three words, the comma is recommended.
- Shortly we will be leaving for the port.
- After his nap Sam felt a lot better.
- After a deliciously long nap in his hammock, Sam felt a lot better.
8 Simple Comma Rules — Remember Them Like Your Own Birthday
Most people have no clue there are eight comma rules. There really are only eight! And no, one does not involve putting a comma in when you naturally pause. Maybe if you are transcribing speech… but even then there’s a 99.9% chance that’s incorrect placing.
You might care about this, you might not. Either way, these comma rules are supposed to guide writing.
I italicized that because I don’t know a single person that is not flawed enough to adhere to every single rule.
It can also get confusing when you’re writing sentences that have multiple elements in them that would constitute a comma. I just like to keep it simple. If it covers more than one of these rules, I go with my gut on which rule takes higher precedence.
In all actuality, I have comma fever. I love commas. I have a problem…
Okay! Here are the rules!
Let’s start simple. Use a comma in your dates to separate date and year. Or to separate days of the week and the date.
- Example: Monday, January 2nd
- Additional Example: June 22, 1993
- Continuing with simple, you put a comma between a city and a state or country.
- Example: Santander, Spain
- Additional Example: Port Angeles, WA
You have the option of putting a comma after an introductory element. I personally think this is completely unnecessary, but what do I know. It works well if someone is pausing and you are quoting direct speech while trying to get a meaning across.
Example: Hi, how are you today?
Overworked and underpaid, how are you?
Hopefully you know this one by now. Put a comma to separate quotes. Don’t be lazy.
- Example: “I told you to rinse the dishes in the sink because you tend to let milk dry,” she yelled from the kitchen to his office.
- Additional Example: “Oops,” he breathed heavily walking into the kitchen, “I’ll remember next time I promise.”
You should also know this one. Any bit of information unnecessary to the conversation is separated in commas.
Example: The bearded man, Ron Swanson, stores bacon in various parts of his office.
This is where the grammar elements get tricky. I didn’t learn what a dependent clause was until it was an age that brought embarrassment. So here. Let me save you if you don’t already know.
Dependent clauses are incomplete (or incomplete thoughts) that cannot function on their own. They might be missing a verb or a subject. They can be prepositional phrases.
Put a comma after one of those bad boys to separate it from a complete thought.
Example: When I was younger, I had a cat named Whiskers the Magical Cat. He went by DC for Danger Cat though.
Remember dependent clauses? They have a friend. A more independent one that owns its own apartment and smokes imported cigars over glasses of straight brandy.
Those are independent clauses. They are essentially sentences that can function on their own. Yes. Use a comma with those bad boys. These ones are typically a bit more challenging because with them comes that annoying party girl that “whoos” loudly when they’ve had too much to drink. Those are called conjunctions.
Conjunctions connect two independent clauses. There are six of them.
- FOR, AND, NOR, BUT, OR, YET, SO (FANBOYS).
- Example: I hate me job, yet I cannot leave it because it pays the bills.
- Additional Example: My dog is incredibly cute, but not when she chews on my houseplants.
Last but not least, use a comma to separate three or more items. You can use two commas for three items, or if you’re like me you obsess over the Oxford Comma. That’s the little comma that can be arguable both necessary and unnecessary, and is after the last item listed in the series. I think it’s crucial.
Example: Growing up I had goats, chickens, turkeys, and geese.
See? Simple enough.
To know them…. Using them and remembering them is harder. It’s okay, I don’t judge your grammar errors.
- And if I do because the error is just that bad, I keep it to myself and judge you in my head…
- And to my dog…
- But she can’t understand what I’m saying anyway.
Rules for Comma Usage
Ah, the comma. Of all the punctuation marks in English, this one is perhaps the most abused and misused. And it’s no wonder. There are lots of rules about comma usage, and often the factors that determine whether you should use one are quite subtle. But fear not! Below, you’ll find guidance for the trickiest comma questions.
What Is a Comma?
While a period ends a sentence, a comma indicates a smaller break. Some writers think of a comma as a soft pause—a punctuation mark that separates words, clauses, or ideas within a sentence.
Here’s a tip: Commas can be tricky, but they don’t have to trip you up. Grammarly’s writing assistant can help you make sure your punctuation, spelling, and grammar are tip-top on all your favorite websites.
Confused about commas?
Grammarly provides real-time suggestions wherever you write.
- With few exceptions, a comma should not separate a subject from its verb.
My friend Cleo, is a wonderful singer.
Writers are often tempted to insert a comma between a subject and verb this way because speakers sometimes pause at that point in a sentence. But in writing, the comma only makes the sentence seem stilted.
My friend Cleo is a wonderful singer.
- Be especially careful with long or complex subjects:
The things that cause me joy, may also cause me pain.
The things that cause me joy may also cause me pain.
Navigating through snow, sleet, wind, and darkness, is a miserable way to travel.
Navigating through snow, sleet, wind, and darkness is a miserable way to travel.
Comma Between Two Nouns in a Compound Subject or Object
Don’t separate two nouns that appear together as a compound subject or compound object.
Cleo, and her band will be playing at Dockside Diner next Friday.
Cleo and her band will be playing at Dockside Diner next Friday.
Cleo will wear a sparkly red blazer, and high heels.
Cleo will wear a sparkly red blazer and high heels.
When a subject or object is made up of two items and the second item is parenthetical, you can set off the second item with commas—one before it and one after it. But you don’t need a comma when you’re simply listing two items.
Comma Between Two Verbs in a Compound Predicate
You get a compound predicate when the subject of a sentence is doing more than one thing. In a compound predicate that contains two verbs, don’t separate them with a comma.
Cleo will sing, and play the banjo.
Cleo will sing and play the banjo.
- This mistake is most common when the predicate is made up of long verb phrases.
By the end of this section, you will be able to:
- Identify the uses of commas.
- Correctly use commas in sentences.
One of the punctuation clues to reading you may encounter is the comma. The comma is a punctuation mark that indicates a pause in a sentence or a separation of things in a list. Commas can be used in a variety of ways. Look at some of the following sentences to see how you might use a comma when writing a sentence.
- Introductory word: Personally, I think the practice is helpful.
- Lists: The barn, the tool shed, and the back porch were destroyed by the wind.
- Coordinating adjectives: He was tired, hungry, and late.
- Conjunctions in compound sentences: The bedroom door was closed, so the children knew their mother was asleep.
- Interrupting words: I knew where it was hidden, of course, but I wanted them to find it themselves.
- Dates, addresses, greetings, and letters: The letter was postmarked December 8, 1945.
You may notice a comma that appears near the beginning of the sentence, usually after a word or phrase. This comma lets the reader know where the introductory word or phrase ends and the main sentence begins.
Without spoiling the surprise, we need to tell her to save the date.
In this sentence, without spoiling the surprise is an introductory phrase, while we need to tell her to save the date is the main sentence. Notice how they are separated by a comma. When only an introductory word appears in the sentence, a comma also follows the introductory word.
Ironically, she already had plans for that day.
When you want to list several nouns in a sentence, you separate each word with a comma. This allows the reader to pause after each item and identify which words are included in the grouping. When you list items in a sentence, put a comma after each noun, then add the word and before the last item. However, you do not need to include a comma after the last item.
We’ll need to get flour, tomatoes, and cheese at the store.
The pizza will be topped with olives, peppers, and pineapple chunks.
The Comma | English Grammar | EF
There are some general rules which you can apply when using the comma. However, you will find that in English there are many other ways to use the comma to add to the meaning of a sentence or to emphasise an item, point, or meaning.
Although we are often taught that commas are used to help us add 'breathing spaces' to sentences they are, in fact, more accurately used to organise blocks of thought or logical groupings. Most people use commas to ensure that meaning is clear and, despite grammatical rules, will drop a comma if their meaning is retained without it.
Separate phrases, words, or clauses in lists
When making a list, commas are the most common way to separate one list item from the next. The final two items in the list are usually separated by “and” or “or”, which should be preceeded by a comma. Amongst editors this final comma in a list is known as the “Oxford Comma”.
A series of independent clauses (sentences)
a series of nouns
a series of adjectives
A list of adjectives usually requires commas. However, if an adjective is modifying another adjective you do not separate them with a comma (sentence 3).
a series of verbs
a series of phrases
Use a comma to enclose non-defining relative clauses and other non-essential details and comments. The comma is placed on either side of the insertion.
A final warning
Commas – The Writing Center • University of North Carolina at Chapel Hill
This handout offers seven easy steps to becoming a comma superhero.
Commas, commas, and more commas
Commas help your reader figure out which words go together in a sentence and which parts of your sentences are most important. Using commas incorrectly may confuse the reader, signal ignorance of writing rules, or indicate carelessness. Although using commas correctly may seem mysterious, it can be easy if you follow a few guidelines.
Beware of popular myths of comma usage:
- MYTH: Long sentences need a comma. A really long sentence may be perfectly correct without commas. The length of a sentence does not determine whether you need a comma.
- MYTH: You should add a comma wherever you pause. Where you pause or breathe in a sentence does not reliably indicate where a comma belongs. Different readers pause or breathe in different places.
- MYTH: Commas are so mysterious that it’s impossible to figure out where they belong! Some rules are flexible, but most of the time, commas belong in very predictable places. You can learn to identify many of those places using the tips in this handout.
You probably already know at least one of the following guidelines and just have to practice the others. These guidelines are basically all you need to know; if you learn them once, you’re set for most situations.
1. Introductory bits (small-medium-large)
Setting off introductory words, phrases, or clauses with a comma lets the reader know that the main subject and main verb of the sentence come later. There are basically three kinds of introductory bits: small, medium, and large ones. No matter what size they are, an introductory bit cannot stand alone as a complete thought. It simply introduces the main subject and verb.
There are small (just one word) introductory bits:
- Generally, extraterrestrials are friendly and helpful.
- Moreover, some will knit booties for you if you ask nicely.
There are medium introductory bits. Often these are two- to four-word prepositional phrases or brief -ing and -ed phrases:
- In fact, Godzilla is just a misunderstood teen lizard of giant proportions.
- Throughout his early life, he felt a strong affinity with a playful dolphin named Flipper.
- Frankly speaking, Godzilla wanted to play the same kinds of roles that Flipper was given.
- Dissatisfied with destruction, he was hoping to frolick in the waves with his Hollywood friends.
There are large introductory bits (more than 4 words). You can often spot these by looking for key words/groups such as although, if, as, in order to, and when:
- If you discover that you feel nauseated, then you know you’ve tried my Clam Surprise.
- As far as I am concerned, it is the best dish for dispatching unwanted guests.
When to Use a Comma before And
If the number of page visits is a reliable indicator, this topic—using a comma before and—is on the minds of many people. The third most oft-visited on this site, this page garnered close to 10,000 hits in the past thirty days.
(The most popular page—with twice as many views—is on en dashes and em dashes, followed by the article on starting sentences with and and but, with 12,000 views. But I digress.)
Here we focus on one of two specific situations that call for the use of a comma before and:
(1) The Comma before and in Lists of Three or More Items
This hotly debated punctuation mark known as the serial comma is also often called the Oxford comma or the Harvard comma. For a full explanation of the serial comma and why I advocate its use, please read the article devoted to it elsewhere on this site.
(2) The Comma before and Joining Two Independent Clauses
An independent clause—also known as a main clause—is a group of words that comprises a subject and a verb and that can stand alone as a sentence. A compound sentence is one that contains two or more independent clauses joined by one or more coordinating conjunctions—most commonly, and.
In the following examples, the independent clauses appear in brackets:
- [Miguel took piano lessons for sixteen years], and [today he is an accomplished performer].
- [We rented lodging for our ski trip to Utah in March], and [later that same day we purchased airline tickets as well].
(Related bonus info: If we omitted the and in each of these sentences but kept the comma, we would end up with a type of run-on sentence called the comma splice.)
Notice in the next example that we do not use a comma before and because it does not join two independent clauses but merely joins two verbs:
- Miguel took piano lessons for sixteen years and today is an accomplished performer.
- We rented lodging for our ski trip to Utah in March and later that same day purchased airline tickets as well.
In each of these sentences, we have only one independent clause—two verbs (took and is in the first sentence and rented and purchased in the second sentence) but only one subject (Miguel and we).
And Is Not the Only Coordinating Conjunction
We need a comma when any of the seven coordinating conjunctions (and, but, or, nor, for, so, yet) join two independent clauses:
- [Tom is not taking his ski helmet on the trip], but [he is taking his new ski pants].
- [We are not concerned about the conditions on the slopes in March], for [the ski season in Utah typically runs through the middle of April].
Length Is Not a Factor
In this next example, even though the sentence is long, we do not need a comma because we have only one independent clause. The conjunction but merely connects the two verbs wanted and could not afford:
- Sigfried wanted to go back to school in August to earn a college degree but could not afford to quit his job and lose both his seniority and his benefits.
Some writers omit the comma before a coordinating conjunction if the two independent clauses are short, as in these examples:
- I drove home but he stayed there.
- The rains came and the rivers rose.
Omitting the comma in such cases is a perfectly acceptable stylistic choice. Nonetheless, although it is not necessary to use a comma before but or and in these sentences, it is not considered wrong to do so since we do, in fact, have two independent clauses in each sentence.
At the End of the Day, Clarity Rules
Sometimes a comma is necessary to prevent a misreading. Consider, for example, this sentence: “We often throw out garbage, and waste energy in doing so.”
Because the word waste can be a verb or a noun, the comma helps a reader avoid misreading it as noun in this sentence, where it is serving as a second verb.
Most people tend to overuse commas, however, so be sure your sentence is truly ripe for misreading before adding a comma in such situations.
Commas before and That Have Nothing to Do with the Conjunction Per Se
Sometimes we may see a comma before and (or another coordinating conjunction) that is appropriate for a reason unrelated to that conjunction.
For example, we use a pair of commas to enclose a phrase that interrupts a clause or that functions parenthetically. A writer may choose to place a comma before and (or any conjunction) when the conjunction launches such a phrase:
- Sarah told him again, and really meant it this time, to turn off the television.
- Alice asked John once, but only once, to forgive her.
We could argue that em dashes or parentheses would be a better choice, but that’s the topic of another article (the most popular one on this site).
Can you tell which of the following sentences need a comma before a coordinating conjunction because it joins two independent clauses?
- The ice storm last week caused tree limbs to fall on power lines and many people were without electricity for days.
- The ice storm last week caused many tree limbs to fall on power lines and left many people without electricity for days.
- Many companies are hiring chief information officers to oversee their information technology systems for only a specialist can keep pace with the rapid changes in technology.
- Shaniqua may stay on campus for the weekend or she may decide to go home to see her high school friends.
- Shaniqua may stay on campus for the weekend or may go home to see her high school friends.
- We knew the roads were becoming treacherous yet we dreaded having to announce that schools would be closed the next day.
- We knew the roads were becoming treacherous yet dreaded having to announce that schools would be closed the next day.
- [The ice storm last week caused tree limbs to fall on power lines], and [many people were without electricity for days].
- no comma
- [Many companies are hiring chief information officers to oversee their information technology systems], for [only a specialist can keep pace with the rapid changes in technology].
- [Shaniqua may stay on campus for the weekend], or [she may decide to go home to see her high school friends].
- no comma
- [We knew the roads were becoming treacherous], yet [we dreaded having to announce that schools would be closed the next day].
- no comma
©2004 Get It Write. Revised 2020.
Rules for comma usage
The comma is perhaps the most puzzling mark of punctuation. The rules for using commas are so numerous and can seem so arbitrary that one often wishes one could dispense with them once and for all. Really, are the commas so vital in the sentence below?
(1) Historically the comma is derived from the diagonal slash which was used to indicate a pause. [incorrect]
(2) Historically, the comma is derived from the diagonal slash, which was used to indicate a pause. [correct]
It seems, indeed, that the commas can be removed in example (1). However, their presence becomes justified if we read the sentence aloud — we make a short pause after the words historically and slash, precisely the places where the commas should be. A useful rule of thumb is to place commas where one makes a pause in speech.
Rule of thumb: a comma indicates a pause in speech.
When in doubts then, read the sentence aloud. If you pause at some place, insert a comma to mark the pause.
- Still, commas are more than simple pause-markers; they help the reader understand the structure of the sentence and resolve ambiguity. Compare the two sentences:
- (3) The students who passed the exam went on a fieldwork trip.
- (4) The students, who passed the exam, went on a fieldwork trip.
The sentence without comma means that only those students who passed the exam went on a trip. The sentence with commas means that all students went on a fieldwork trip, and they all, by the way, passed the exam.
- Below follow a few rules about how to use commas correctly.
- Rule 1: Use commas in a series of three or more items.
- Normally, the last item in the series is preceded by and, or, or nor.
- (5) The new regulations concern students, research fellows, and post-doctoral researchers.
- The comma placed before and (or, nor) is not obligatory, but it is recommended because it sometimes disambiguates the sentence.
- (6) Tom’s favorite dishes are tomatoes, fish and chips, and toasts.