Colons may be followed by a phrase, a list, a quotation, or even another independent clause.
Read on to familiarize yourself with how to use both colons ( : ) and semicolons ( ; ) in academic writing.
The colon is used to introduce a list after a complete sentence.
We have three levels of government: municipal, provincial and national.
The biscuit recipe calls for these ingredients: flour, butter, baking powder, and milk.
Although the battle at Dieppe was a disaster, it served some useful purposes: it distracted the enemy from the Eastern front, it taught the Allies about the importance of reconnaissance, and it gave the inactive Canadian troops in Britain something to do.
2. Long Quotations
Colons are also used to introduce long quotations.
Bettelheim (1975) explains the importance of fairy tales to children’s development:
Today, as in the past, the minds of both creative and average children can be opened to an appreciation of all the higher things in life by fairy tales, from which they can move easily to enjoying the greatest works of literature and art. (p. 23)
Note: Colons should be used sparingly, especially as a means of introducing single sentence quotations. Rather, try to integrate the quotation into the syntax of your sentence.
3. Connect two sentences if the second is a restatement or further explanation of the first.
Minds are like parachutes: they only work when they are open.
I devised a new exercise plan: I would get up early and jog every morning.
4. Other Uses of the Colon
The other uses of the colon are very specific.
i) Colons are used to follow salutations in formal and business letters.
Dear Dr. Jones:
ii) Colons are used between the hour and the minutes in time expressions.
6:45 p.m.
He ran the marathon in 4:27:53.
iii) Colons are used between main titles and sub-titles.
1. A colon should not come after a verb like is or are. This is wrong because a complete sentence is needed before a colon.
This is wrong:
The causes of Cathy’s success are: her intelligence, her hard-working approach, and her high level of motivation.
Explanation: “The causes of Cathy’s success are” is not a complete sentence.
This is fine:
Cathy is successful for a number of reasons: her intelligence, her hard-working approach, and her high level of motivation.
Explanation: “Cathy is successful for a number of reasons” is a complete sentence.
You may see examples of colons being used after incomplete sentences in novels, newspapers and magazines, but in formal academic writing, you must have a complete sentence before a colon.
2. A colon cannot be used to introduce a list in the middle of a sentence, only at the end of a sentence.
This is wrong:
John bought some groceries: tea, eggs and lettuce, for his mother.
This is fine:
John bought his mother some groceries: tea, eggs and lettuce.
3. A colon cannot be used to separate complete sentences. A semi-colon (;) is used for that.
This is wrong: He loves her: she loves him.
This is fine: He loves her; she loves him.
The semicolon is the most misused and misunderstood piece of punctuation. Essentially, semicolons exist only to join independent clauses (i.e., complete sentences). Picture it as a period sitting on top of a comma. The period signals that the semicolon must be preceded by an independent clause; the comma indicates that the semicolon intends to link related elements into a single sentence.
In order to use a semicolon, the sentences must not only be short but also have an obvious connection in meaning.
Anna loves figure skating; she hates hockey.
He loves her; she loves him.
Frank burnt himself; he still has the scar.
1. Between two complete thoughts before a transition word or phrase
When a conjunctive adverb (e.g., however, nevertheless, therefore, thus) or a transitional phrase (e.g., for instance or in fact) appears between two independent clauses, it must be preceded by a semicolon, and is usually followed by a comma.
Bring your I.D. card; otherwise, you won’t be allowed in.
She does a lot of traveling between semesters; for example, on the last semester break, she went to Mexico.
Princess Leia senses a mystic connection with Luke Skywalker; in fact, she is his sister.
Subordinators (e.g. because, when) and coordinators (e.g. and, or, but, so, for, yet) cannot be used with a semi-colon. However, a semicolon may take the place of one of these joining words.
2. Between items in a list
Usually commas are used to separate items in a list. However, sometimes commas are needed within items in a list; in those cases, semicolons are used to separate the listed items.
I am struggling to decide what university to attend: U.B.C., which has a big beautiful campus; S.F.U., which is close to my home; or U.C.F.V., which is smaller and more personal.
A general rule of thumb – when a pause is needed in a sentence for the meaning to be clear, you probably need a comma. Many people rely on this rule of thumb entirely. However, the rule of thumb method does not always work. This handout shows the rules around comma use.
Read below for lots more help:
A comma is used after introductory words, phrases or clauses. Another way to look at it is that commas come before the main subject of a sentence. In this way, the comma is a sign to the reader that the main subject is coming.
Words: Unfortunately, our picnic was rained out.
Phrases: Laughing to himself, he drew a cartoon.
At 6:00, the family sat down to dinner.
In conclusion, the law needs to be changed.
Clauses: After she finished her paper, she fell into bed and slept.
If I won the lottery, I would travel.
Because we had never met, we felt awkward at first.
She invited Amanda, Amy, Nick and Claire to her party.
Strawberries, watermelon and apricots are my favorite fruits.
A student has to go to class, take notes, read textbooks and write exams.
The shift changes at midnight, eight in the morning and four in the afternoon.
Note: In these lists, a comma has not been used before the and. However, some people prefer to use commas before the and.
For example:
She invited Amanda, Amy, Nick, and Claire to her party.
Although either with or without the comma is acceptable, it is good to be consistent.
A comma is used before a coordinator which joins two independent clauses. An independent clause expresses a complete thought, like a simple sentence. The only coordinators are for, and, nor, but, or, yet, and so.
A good way to remember these coordinators is to remember the phrase FAN BOYS.
For They went to a fancy restaurant, for it was his birthday.
And He ordered salmon, and she ordered pasta.
Nor He didn’t have soup, nor did he order anything to drink.
But She wanted to have oysters, but the restaurant had run out of them.
Or Would you like dessert, or would you prefer to get your bill?
Yet They loved the chocolate cake, yet the pieces were too big to finish.
So The service was excellent, so they left a big tip.
Note: The comma is optional when both independent clauses are short.
Remember that commas are used only when the coordinator joins two separate subject/verb combinations. If a sentence has one subject with two verbs, you should not use a comma.
For example, She sat down and ordered a coffee.
This does not need a comma as there is only one subject.
Similarly, if the sentence has two subjects but only one verb, no comma is used.
For example, The angry woman and her crying children left the store without any groceries.
When information is added to a sentence and that information interrupts the flow of ideas of the sentence, commas are used to separate the interruption from the rest of the sentence.
Here are some examples:
Julie Payette, for example, is an excellent role model for girls.
Marc Garneau, on the other hand, is famous because he was Canada’s first astronaut.
John A. McDonald, Canada’s first Prime Minister, had a drinking problem.
Justice Institute of British Columbia is in New Westminster, B.C.’s first capital.
A salmon, its sides gleaming, struggled up the river.
Nick, who struggled with grades in high school, is doing quite well in college.
Many downtown eastside residents use the Carnegie Centre, which sits at Hastings and Main.
To decide whether something is an interrupter, you should try taking those words out of the sentence. If you can take them out and the meaning of the sentence is still clear, you have an interrupter. However, if you take the words out and the meaning is no longer clear, there is no interrupter, and you don’t need commas.
For example:
Sir Wilfred Laurier, who was a past prime minister of Canada, is pictured on our five dollar bill.
Notice that if you take out who was a past prime minister of Canada, the meaning of the main sentence is still clear. Who was a past prime minister of Canada is extra information, not essential to understanding the main sentence. Even without it, we know whose picture is on the five dollar bill.
However, look at this sentence:
The man who lives down the street got arrested.
Notice if you take who lives down the street out of this sentence, you don’t know anymore who was arrested. Who lives down the street is needed to identify the man. For this reason, who lives down the street is essential information, and no commas are used.
Commas separate direct quotes from your own writing.
She said, “Pasteur really made a difference.”
“Expect snow overnight,” predicted the TV weather reporter.
“Hockey,” explained Sam, “is my favorite winter sport.”
Commas are used when you directly quote a complete idea. When only a word or phrase is quoted, you don’t need commas.
She described the television as an “idiot box."
Commas are also not used when you report what someone said using indirect speech.
Sam explained that hockey was his favorite winter sport.
Time: September, 1980
January 1, 2000
Monday, June 14, 1999
4:30, December 31
6:42 a.m., July 27, 1985
Numbers: 1, 364
23,900,000
Note that commas with numbers have become optional in science and mathematics.
Place: Paris, France
Moose Jaw, Saskatchewan
3652 Main Street, Vancouver
700 Royal Ave., New Westminster, BC, V3L 5B2, Canada
The most straightforward way to proofread for commas is to read your writing out loud. When you need to pause slightly to make the writing make sense, you probably need a comma. However, be cautious because over-use of commas is a more common problem than under-use. Whenever you are in doubt about whether a comma is needed, refer back to the rules in this handout to help you make your decision. Remember that when you have a list of two items in a list, there is not a comma before the second item.
By Lynne Truss. Available for loan from JIBC Library.
Some writers may write sentences that contain two complete ideas, punctuated only with a comma or with no punctuation at all. Both are wrong.
A complete sentence (also known as an independent clause) is a sentence that can stand on its own.
A run-on sentence, or a comma splice, occurs when two complete sentences are written together with no punctuation or with only a comma to separate them.
Look at the sentences below. They are examples of run-on sentences and comma splices.
1. You can insert a period to make the two complete sentences separate.
Example:
She walked the dog. He fed the cat.
2. You can insert a semicolon. Only use a semicolon if the two sentences are closely related.
Example:
I’ve always wanted to go to Reno; it’s wonderful there.
3. You can add a word such as and or therefore after inserting a comma or a semicolon.
These words will need a comma before the word: and, but, for, or, nor, yet, so.
Words such as however, nevertheless, therefore, finally, etc. will need a semicolon and a comma.
Example:
She walked the dog, and he fed the cat.
I’ve always wanted to go to Reno; however, I haven’t gone yet.