Punctuation rules

- An introductory prepositional phrase defines the direction, time, location, or spatial relationship of the main clause. It is dependent on the main clause and cannot stand alone as a phrase. There must be a comma after the introductory prepositional phrase if it contains five or more words.

After the big family dinner, we wanted to sleep. (introductory prepositional clause), (main clause)
In the sprawling city park, there is always someone having a picnic.

- However, if the introductory prepositional phrase contains four or fewer words, a comma is not necessary:

While on duty the officer fell asleep.

- There may be cases where a comma isn’t necessary but adds clarity to the phrase. In the phrase below, readers may think “night owls” is a single concept if the comma is excluded.

In the night owls attack mice.
In the night, owls attack mice.

- An infinitive phrase starts with the infinitive form of a verb and is connected to a main clause.

To get a better view of the match, Sarah changed seats. (introductory infinitive phrase), (main clause)

- There are three possible grammatical patterns a sentence with an infinitive phrase may take. First is an introductory infinitive phrase that is followed by the main clause. This requires a comma after the introductory phrase.

To earn more money, John applied for a second job.
To learn Spanish, Euan moved to Argentina.

- Secondly, an infinitive phrase may interrupt the main clause. In this case, commas are required to offset the infinitive phrase.

That idea, to be perfectly honest, will not work well.
This park, to let you know, is a little scary at night.

- The third pattern is when the infinitive phrase comes after the main clause. There is no need for punctuation between the two sentence parts.

I completely forgot you wanted to see that new movie.
The cat is happy to see you.

A participle phrase begins with either a present or past tense participle. They always function as adjectives and add description to the phrase.

Jasmine stared out at the ocean, crashing its waves against the cliffs, and wished it were warm enough to swim.
The bird’s song lasted all morning, echoing in the valley, as Stephanie took pictures for the ornithology society.

Present tense participles end in –ing:

Chewing, dancing, laughing

While regular past tense participles end in –ed:

Chewed, danced, laughed
Irregular forms:
singing sang
becoming became
breaking broken

*It must be noted that irregular past tense participles will not follow a common form.

- When an introductory phrase begins with a subordinating conjunction (such as: even, as soon as, if, provided that, once), there is a comma after the introductory phrase. However, there is not a comma after the subordinating conjunction.

Common subordinating conjunctions:
as soon as because whenever
as long as Just as wherever
after once now that
although if unless
provided even until

- An introductory phrase beginning with a subordinating conjunction is dependent on the main clause. Whether the dependent clause is before or after the main clause, the subordinating conjunction comes at the beginning of the dependent clause.

Even if it’s cold, we are going on a hike.
Although I’ve seen it before, I’ll see that movie with you tomorrow night.
As soon as it stops raining, you need to take out the garbage.

- Conjunctive adverbs 1) link two independent clauses in the same sentence, 2) link ideas in two or more sentences, and 3) show connections between ideas within a single independent clause.

Common conjunctive adjectives include:
nevertheless similarly however also
nonetheless finally therefore indeed
consequently likewise moreover then
furthermore hence otherwise thus

- When a conjunctive adverb is used to link two independent clauses, it is preceded by a semicolon and followed by a comma.

You’re my brother; nonetheless, I feel like you’re taking advantage of me.
Tuition increases have prompted many American students to look for educational opportunities outside of the Unites States; furthermore , many European countries provide free higher education to non-European citizens.
Sea turtles are an endangered species; however, many people still illegally kill them and takes their eggs on beaches around the world.

- If a conjunctive adverb is used anywhere else in a phrase, it is off set by commas.

Malina had no alibi for the murder. Nevertheless, she maintained her innocence throughout the trial.
Finally, the ship was cleared to set sail.
I went to the store. Meanwhile, Catherine made us lunch.

- An interjection conveys an emotion or feeling, and they are rarely seen in academic and formal writing. The interjection usually appears at the beginning of a sentence or clause with little connection to the rest of the phrase. They are most often followed by an exclamation point or comma.

- The interjection is followed by an exclamation point when it conveys very strong emotions like delight or surprise.

Ouch! Claire just bit me.
Whoa! I can’t believe you did that.
Yay! This is such exciting news.

- In most other cases, the interjection is offset by commas. This includes when an interjection is found in the middle of a sentence.

Well, let’s see what we can do.
Here, I’ll help you with those boxes.
I’ll need more time to finish this project, well, I think I’ll need extra time.

Coordinating conjunctions connect items, phrases, or clauses. They are used to give equal weight to each phrase. Coordinating conjunctions are easily remembered with a simple acronym:



- When a coordinating conjunction separates two main clauses or verbs, a comma precedes it. The second main clause needs to be an entirely independent clause, with a subject and verb, if you are to put a comma before the coordinating conjunction. Otherwise, don’t use the comma.

The pasta looked delicious, but the family ordered lobster.
It was raining outside, yet I went for a run.
I was very excited, and fairly nervous.
They ran as fast as they could, and jumped as high as possible.

- Finally, when it is used to separate two items there is no punctuation.

I ordered potatoes and French fries.
There are hats and gloves inside.
You may eat this with a spoon or a fork.

When two independent clauses are not connected with a conjunction or another transitional expression, a semicolon is used to separate them. The semicolon works as a light period between the phrases; nonetheless, it keeps the two independent clauses in the same sentence. Both the independent clauses need to be able to operate as complete sentences if you are to use a semicolon.

The party appeared to be a huge success; all the cake had been eaten quickly.
The party appeared to be a huge success; all the cake had been eaten quickly.

- A non-restrictive clause provides non-essential information to the meaning of a sentence, and is offset by commas. It usually adds interesting information to the sentence, and it can be removed easily as well.

My sister, who is a lawyer, will help me move tomorrow.

- The information here concerning where the sister lives is non-essential. The sentence makes just as much sense without it.

My sister will help me move tomorrow.

- The information offset by commas must be non-essential to understanding the phrase; if it’s essential information, do not use commas. For example, if the sister’s profession actually tells us which sister is helping, instead of just adding something of interest, it becomes essential information.

My sister who is a lawyer will help me move tomorrow. (Instead of the sister who is, say, a teacher).

Question tags are placed at the end of statement in a way that transforms it into a question. They are often used when the speaker expects that the person with whom they’re speaking will agree with them, and they are used almost exclusively during informal interactions. Question tags are always separated from the main clause by a comma.

It’s beautiful outside, isn’t it?
I’m so proud of Sophia, aren’t you?
Let’s have some tea, shall we?
You’ve met him before, haven’t you?
It isn’t very good, is it?
That’s very interesting, yeah?

When a phrase contains a part that is in contrast with the subject, this part is offset by commas. Look for words like not, unlike, and never to signal a contrast to the subject.

A green light, not red light, means go when driving.
Today, unlike yesterday, is very cloudy.
Erin, unlike Kira, is very studious.

- Commas are used only sometimes for dates, dependings on the information provided. When a phrase contains only the month and year, no punctuation is needed. These less-specific dates are also frequently preceded by "in."

I visited Vietnam in May 2011.
Signe graduated from high school in June 2007.

- When the day of the month is also included, there must be a comma between the day and the year. These specific dates are frequently preceded by "on."

The ceremony took place on May 17, 2001.
I arrived in France on August 26, 2015.

- Furthermore, if the day of the week is included, there is a comma after it.

The grocery store will be closed Wednesday, July 13, 2016.

- An appositive is a noun or a pronoun that is set next to another noun or pronoun and is used to describe or identify it.

The girl in the toy store commercial is my daughter (noun) + (appositive)
The tree with blue flowers needs to be removed from my garden. (noun) + (appositive)

- The appositive is offset by commas when the information is non-essential to understanding the phrase. If it’s essential information, do not use commas. For example, take the two sentences below:

My sister the lawyer will help me move tomorrow.
My sister, the lawyer, will help me move tomorrow.

- For example, if the sister’s profession actually tells us which sister is helping, instead of just adding something of interest, it becomes essential information.

- There must always be a comma before a direct quotation is inserted in a text.

She said, “I’ll never go back!”
“He’s a great man, ” Humphrey shouted.

- If there is an interruption in the quote, it i’s offset by commas. Following American grammar rules, the comma preceding the interruption is placed inside the quotation marks. However, this may vary depending on the country.

“How dare you,” she screamed, “speak to me in such a manner!”

- If the quote is not from someone specific, but instead refers to a general statement do not include a comma.

I don’t like it when people yell “shut up” at me. I find it rude.

- In this example, the speaker is not directly quoting someone, and is instead making a general statement. Furthermore, it isn’t an entrance to a dialogue.

You also don’t need a comma if you are not using a verb that introduces a direct quotation. While you will always need a comma after verbs like "said," "shouted," "scolded," and "pleaded," constructions like "she asked me to" and "he explained that" don’t take a comma before the quotation.

I can’t believe yesterday she told me to "make myself useful."
She said, "make yourself useful" to me yesterday.

Lastly, Punctuation almost always goes inside the quotation marks.

Michael begged, "I really don’t want to go back to that school."
My mom asked me, "Will you be home for Thanksgiving this year?"
Did she really say, "You can’t sit with us"?

The last example has the question mark outside the quotation because, while the quotation is a positive statement, it’s the sentence itself that is interrogative. The speaker wants to know if the person in question made a particular statement.

- "Et cetera" is Latin and is usually abbreviated as "etc." It’s used for two reasons: when the omitted material is obvious, and when additional information is unnecessary.

- When used at the end of a sentence, it is preceded by a comma and followed by a period.

I have all the necessary items to make a cake, like flour, sugar, etc.
You’ll find tissues in the bathroom, living room, kitchen, etc.

- If the et cetera appears in the middle of a phrase it is followed by a period and a comma.

I ate so much chocolate, fudge, cake, etc., that I gave myself a stomach ache.

- Interrupters are small word group that convey tone, emotion, or emphasis in a sentence. They are offset with commas without commas the sentence flow would be awkward. Reading sentences aloud often helps determine if there is an interrupter or not.

Common interrupters include:
Generally speaking To say the least unfortunately
In fact happily indeed
As they say sadly (name of a person)
I am, needless to say, happy to see you.
Brooke, sadly, has been placed in a psychiatric hospital.
In my experience, generally speaking, there isn’t a long line.

There must be a comma before or after a name when it’s included at the beginning or end of a sentence.

Jane, have you found the keys yet?
I’ll let you know later, Tom.
George, you’re the best!

- Coordinate, or paired, adjectives are two or more parallel adjectives used to modify a noun. Commas are used to separate these kinds of adjectives. There are ways to test whether or not the sentence contains coordinate adjectives.

- Firstly, sentences with coordinate adjectives still make sense if you replace the commas with the word and. If there are just two coordinate adjectives, separate them with the word and.

The girl was sweaty and gross.

- This example shows that this phrase is, in fact, a series of coordinate adjectives:

The boy was covered in gross, stinky, sticky mud.
The boy was covered in gross and stinky and sticky mud.

- Secondly, if you can switch the order of the adjectives without compromising the meaning of the sentence, they are coordinate adjectives.

I was looking at the tall, funny building.
I was looking at the funny, tall building.

- On the other hand, adding the word and or changing the adjective order of noncoordinate adjectives confuses the meaning of the sentence. No commas are needed between this kind of adjective.

The red sports car zoomed past them. [correct]

- Notice that if you change the order or add the word “and,” the sentence no longer makes sense.

The red and sports car zoomed past them. [incorrect]
The sports red car zoomed past them. [incorrect]

- This shows that "red" and "sports" in the above sentence are not being used as coordinate adjectives.

- When putting an address in a sentence, each element is separated by a comma. The standard American address breaks down into these parts:

1023 Patterson Avenue
Eugene, Oregon 97405

- In a sentence this address will contain a comma after the street number and street name, and after the city. If the sentence continues, there must also be a comma after the zip code.

Ricky lives at 1023 Patterson Avenue, Eugene, Oregon 97405.
Ricky moved to 1023 Patterson Avenue, Eugene, Oregon 97405, about a year ago.

- There are two ways to punctuate salutations at the start of a letter, depending on how formal it is. The general rule is to place a comma after the name; however, a semicolon may be used in formal writings instead.

Dear Ms. Johnson,
or Dear Ms. Johnson:

- Commas are also inserted between a person’s name and post-nominal letters (academic degrees, certifications, affiliations, etc.). Keep in mind, there’s no comma between the abbreviations for junior or senior.

Mr. Bradford, MD,
Mr. Lidon Jr.,

A letter closes with a complimentary closing followed by a comma (and usually a signature on the next line). The complimentary closing may be rather informal or very formal.

Rebecca Chatsworth
Best Regards,
Kiralyn Peterson
Richard Hoggart
Sincerely yours,
Abigail Midelfort
Kind regards,
Lindsay MacDonald
Philip Hayfield

Correlative conjunctions connect two parallel items in a sentence. Pay careful attention to the fact that both parts of the sentence actually carry equal weight. Here are some common correlative conjunctions:

either… or
neither… nor
both… and
whether… or
not only… but also
Either I leave or she does.
Neither Michael nor I own a car.
The cat is both gentle and wild.
Not only am I an exceptional driver, but I’m also great at parallel parking.

When the subject of a sentence is actually composed of two or more nouns or pronouns (e.g. Kate and Mike), there is no comma to separate the two. This is true whether the nouns are separated by the word and, or the word or.

Kate and Mike love their new house.
Mom or her friend will come pick you up later.
The dog and the cat play together all the time.

Depending on the sentence surrounding the parentheses, there may either be one comma after the closing parentheses or none required. If the sentence doesn’t need a comma, once the parentheses are taken out, you should not add one. However, if there is a comma needed, it should be placed at the end of the parenthesis.

They were counting (very loudly I might add) how many eggs were left.
They were counting eggs (very loudly I might add), but they didn’t have enough for breakfast.

Nominal groups are word groups that provide information about people, places, and concepts. Also called noun phrases, nominal groups shouldn’t be split up by a comma because they will lose their meaning. You will need commas when there is a series of noun phrases in one sentence.

Example of a nominal phrase:

a bank account
my mother’s maiden name
a yellow house
I want a blue shirt, a portable vacuum, and a pretty dress to dance in for Christmas.

In the sentence above, there are three nominal groups in a series.

- When the phrase includes only two verbs, separate them by the word and, with out any punctuation. Commas are required after each verb in the series once the series includes three or more verbs. If there’s already a comma after each verb, use semicolons to separate each verb in the series.

- Two verbs in a series:

I ran and swam yesterday.
He drove over and parked the car.

- Three or more in a series:

You will empty the trash, clean the bathroom, and call your grandmother this afternoon.
The children played at the park, ate lunch, and walked back home.

- A case with semicolons:

She ran in the morning, without any shoes on; stepped on some glass, which surprised no one; and spent the afternoon getting stitches.

- In a series such as "cats, dogs, and elephants," the comma after "dogs" is called the "Serial" or "Oxford" comma. It makes sentences clearer, and is thus preferred in written English. You may see sentences without the final comma, however, and can choose to omit it and still have a grammatically correct sentence by writing "cats, dogs and elephants."

Commas shouldn’t be used in a comparison. Writers often place a comma after a conjunction in comparison phrases; however, this is incorrect.

This soda is bigger than your water bottle.
This bag weighs more than my suitcase.

- There are two places you will never, without exception, see commas. They should never separate the subject and the verb of a sentence, and should never be the start of a sentence. While commas are rarely mistakenly placed at the start of a sentence, we often see commas cropping up between the subject and the verb. This mistake frequently occurs when the subject clause is long or already has a verb in it.

The way to check if you’re on the right road is to use GPS.

- With the above sentence, you may be tempted to add a comma after "road"; however, this is incorrect. The verb of the sentence is to be and the subject is the way to check if you’re on the right road

- There should never be a comma after a conjunction that is followed by a phrase.

I can’t say if the weather will be clear tomorrow.
I always wash my hands if I see someone near me cough.