Academic English > Grammar > Punctuation
Knowing how to use punctuation properly is an important skill for writing in English for academic purposes.
Appropriate punctuation acts like a set of ‘road signs’ to guide the reader through the ideas expressed in your sentences. Punctuation marks can tell the reader when to slow down, speed up and stop. By breaking up your sentences, they contain and structure your ideas.
Hyphen and Dashes
The hyphen ( – ), en dash ( – ), and em dash ( — ) look similar but are of different lengths. They also perform different functions.
Only the hyphen receives a dedicated key on most computer keyboards. The method of inserting the other marks varies based on your word processor.
Hyphen
En dash
Em dash
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Pausing Points
Pausing points include the comma, semicolon, and colon.
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The general rule is that a sentence ends with only one terminal punctuation mark. There are three options:
Period
Question mark
Exclamation point
Other Points
Parentheses
Apostrophe
Slash
Angle brackets
Braces
Quotations
This section includes three punctuation marks most commonly used for quotations. All three marks have uses outside of quotations, as well.
Quotation marks
Ellipses
Brackets
. Full stop (a “period”)
? Question mark
! Exclamation mark
, Comma
‘ Apostrophe
” Quotation marks
: Colon
; Semicolon
– Dash
– Hyphen
Full stops [.]
1. Full stops are used to show the end of a sentence.
Hockey is a popular sport in Canada.
The federal government is based in Ottawa.
2. Use a period after certain abbreviations.
B.C. is the province located on the West Coast.
Dr. Bethune was a Canadian who worked in China.
The company is located at 888 Bay St. in Toronto.
It is 4:00 p.m. in Halifax right now.
Question Mark [?]
Use a question mark at the end of a sentence to show a direct question.
How many Emirates are there in the UAE?
Note: do not use a question mark for indirect questions.
The teacher asked the class a question.
Exclamation Mark [!]
Use an exclamation mark at the end of a sentence to show surprise or excitement.
We won the Stanley Cup!
The forest is on fire!
Note: in academic writing exclamation marks should be kept tp a minimum.
Comma [,]
Commas are used to denote a weak pause in a sentence. If you find that you write in long sentences, check whether it might be better create several short sentences replacing commas with full stops. (If you do this you must also check that the verb forms make sense.)
1. Use a comma to show a pause in a sentence.
Therefore, we should write a letter to the prime minister.
2. Use a comma with quotation marks to show what someone has said directly.
“I can come today,” she said, “but not tomorrow.”
3. Use commas for listing three or more different things.
Ontario, Quebec, and B.C. are the three biggest provinces.
4. Use commas around relative clauses that add extra information to a sentence.
Emily Carr, who was born in 1871, was a great painter.
Commas are used to break up different parts of a sentence. They allow someone to make sense of what they are reading. Commas occur where ideas are grouped, to make it easier to understand these ideas. It may be helpful to think of commas as places where a reader might draw breath. The comma forms a natural place in a sentence where the reader can pause, to make sense of an idea. As a comma signifies a pause, it follows natural speech pattern. Here are some of the ways it can be used.
To separate words in a list:
He lost his house, his heritage, his hair, and his handkerchief.
To separate parts of a sentence:
Firstly, I would like to consider the merits of supplementing the diet with zinc extract. Secondly, vitamin C can be introduced to combat infection.
Here the comma separates the first word from the body of the sentence, to indicate that this idea is only the first.
To separate two parts of a linked idea:
After the French Revolution had taken place, many other European countries were concerned about civil unrest.
Many scientists believe in evolution, although some are trying to disprove Darwin’s Theory of Evolution.
To separate a final phrase, which is an afterthought:
Few people enjoy arduous and demanding exams, especially on Saturdays.
I would like to run the London Marathon, if I were fit.
Apostrophe [‘]
1. Use an apostrophe to show ownership of something.
This is David’s computer.
These are the player’s things. (things that belong to the player)
Note: For nouns in plural form, put the apostrophe at the end of the noun.
These are the players’ things. (things that belong to the players)
2. Use an apostrophe to show letters that have been left out of a word.
I don’t know how to fix it.
Apostrophes have three uses in English:
1. They are used to indicate possession, whether literal or figurative.
2. They are used to indicate time and measurement in some cases.
3. They are used to form contractions.
POSSESSIVE APOSTROPHES
Possessive apostrophies show ownership of something and are used in conjunction with the letter s. For example, John’s pencil shows that John has a pencil. You can perform a simple test to determine the location of a possessive apostrophe by rephrasing with have or has.
My mother has a sweater.
My mother’s sweater… (The apostrophe follows mother.)
John has a Toyota Landcruiser
John’s Toyota Landcruiser… (The apostrophe follows the name John.)
The Writing Center has a coffee pot.
The Writing Center’s coffee pot… (The apostrophe follows Center.)
In the above examples, the possessive is made by adding an apostrophe plus an s to the word that possesses. However, if the word already ends in s, whether plural or not, it is acceptable to add an apostrophe only.
The Jones have a Honda.
The Jones’ Honda… (The apostrophe follows The “Jones”.)
James has an iPhone 6.
James’ iPhone 6… or James’s iPhone 6… (The apostrophe follows James.)
The twins have kittens.
The twins’ kittens… (The apostrophe follows The twins.)
TIME AND MEASUREMENT APOSTROPHES
Time and measurement apostrophes indicate time value and measurement in certain uses. Again, the location of the apostrophe can be determined by rephrasing, this time using the word of.
the society of today
today’s society
the heat of the summer
the summer’s heat
the worth of ten dollars
ten dollars’ worth
CONTRACTION APOSTROPHES
Contraction apostrophes make two words into one for ease of conversation by replacing some letters in one or both of the words being combined.
! However, do not use contractions in your academic writing.
do not becomes don’t
I would becomes I’d
would have becomes would’ve
I will becomes I’ll
Make sure the apostrophe is placed where the letter(s) have been omitted and not between the two words. For example, in the contraction of does and not, the apostrophe replaces the o in not: doesn’t.
Note: the contraction of will and not is won’t. Even though some letters are omitted from will, and an o is added, the apostrophe is placed only where the letter o is omitted from not.
BE CAREFUL! Some words that are contractions sound exactly like words that are not. For example, the words it’s (from it is) and its (the possessive form of it), along with you’re (from you are) and your (the possessive form of you) frequently cause problems. If it makes sense as two words, then it’s probably the contraction you’re dealing with.
Finally, while contractions are usually words like we’re, I’m, shouldn’t, and so on, they’re often made up of names, places, seasons, and the like, as in the following sentence:
Summer’s over, and Sheila’s going back to where life’s a bowl of oatmeal and Friday’s the first day of the week.
Quotation Marks [“]
Use quotation marks to show what someone has said directly.
The prime minister said, “We will win the election.“
“I can come today,“ she said, “but not tomorrow.“
Colon [:]
1. Use a colon to introduce a list of things.
There are three positions in hockey: goalie, defence, and forward.
2. Use a colon to introduce a long quotation.
The prime minister said: “We will fight. We will not give up. We will win the next election.”
Semicolon [;]
1. Use a semicolon to join related sentences together.
The festival is very popular; people from all over the world visit each year.
2. Use a semicolon in lists that already have commas.
The three biggest cities in Canada are Toronto, Ontario; Montreal, Quebec; and Vancouver, B.C.
Dash [-]
Try to minimise the use of dashes in your formal work. They can give the impression of a style that is too chatty. They may be used in pairs to insert an explanatory comment or a short list:
Each member of staff – from the most junior to the Chief Executive – is invited to comment on the plans.
Dashes should not be used as a substitute for parentheses – or mixed with them.
Hyphens are used to connect prefixes to words (for example, CD-ROM drives) or when forming compounds such as “second-in-command”.
1. Use a dash before a phrase that summarizes the idea of a sentence.
Mild, wet, and cloudy – these are the characteristics of weather in Vancouver.
2. Use a dash before and after a phrase or list that adds extra information in the middle of a sentence.
The children – Pierre, Laura, and Ashley – went to the store.
Most Canadians – but not all – voted in the last election.
3. Use a dash to show that someone has been interrupted when speaking.
The woman said, “I want to ask – ” when the earthquake began to shake the room.
Hyphen [-]
1. Use a hyphen to join two words that form one idea together.
sweet-smelling
fire-resistant
2. Use a hyphen to join prefixes to words.
anti-Canadian
non-contact
3. Use a hyphen when writing compound numbers.
one-quarter
twenty-three
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Using the Semi-Colon ( ; )
The semi-colon contains a comma and a full stop. It may be helpful to think of semi-colons as halfway between the two. They are used in the following ways:
To link sentences that are closely related:
The night sky was the deepest sapphire; Claire realised that she had not observed its beauty until now.
A full stop between the two sentences would detract from Claire’s observation, and a comma would not make enough of a break to allow the reader to make sense of the two ideas.
To link sentences that are in opposition to each other:
His research methods were fundamentally flawed; nonetheless, he collected the data.
In each of the examples above, the set of words after the semi-colon must be able to stand as a sentence on its own. However, there is a very common use of the semi-colon where this is not the case:
To separate items in a list:
Mrs Brown was assisted by other members of staff: Dr Benham from Animal Husbandry; Mr Gleeson from Botany; and Dr Chalk from Soil Science.
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Using the Colon ( : )
When a colon is used in a sentence, the parts it separates do not need to be complete sentences in their own right. Colons are used in the following ways:
To introduce a list:
The results of the indoor team games were as follows: Wessex came first, Bridges and Wantage were joint second, and Sibly came last.
To link two sentences thematically:
Psychological studies into domestic violence are usually centred on an idea of the nuclear family: Henry Davis decided that he should undertake a more radical approach to research in this area.
Here the two sentences could exist separately, but by connecting them with a colon the reader is led from one idea to the next.
To draw out a conclusion:
Language acquisition is a difficult but immensely rewarding task: without it, there is little hope for global communication.
Here, what is said in the first sentence is contextualised by what is said in the second sentence.
Using the Apostrophe ( ‘ )
The apostrophe has two functions:
To show that letters are missing. This is known as contraction.
To indicate ownership. This is known as possession.
Contractions
When letters are missing in a word, and the word becomes shorter, the apostrophe is used to show where the missing letters belonged.
For example:
I am becomes I’m
You will becomes you’ll
They would becomes they’d
Contractions are used in informal writing. Essays and reports should not contain informal writing.
Possession
Apostrophes are also used to show that something belongs to something else.
For example:
The girl’s hat – means that the hat is owned by the girl.
The girl’s hats – means that the girl owns more than one hat.
The girls’ hat – means that the girls all share ownership of one hat.
The girls’ hats – means that the girls own several hats (or one each).
As you can see, the apostrophe usually comes before the ‘s’ if the subject is single (‘the girl’), and after the ‘s’ if it is plural (‘the girls’). However it may be different if the word for a single subject ends with ‘s’ like princess, Venus or Socrates. One useful way to deal with this is to see if the ‘s’ is pronounced.
For example:
Venus’s arms or the princess’s coronet
In both of these examples the ‘s’ is pronounced, so there is an additional ‘s’ with the apostrophe before.
Socrates’ wife
In this example the ‘s’ is not pronounced, so there is no additional ‘s’ and the apostrophe goes after the final ‘s’ in Socrates.
Common problems with the apostrophe
Its/it’s
The cat licked its paws.
There is no need for an apostrophe, because ‘its’ is a pronoun in its own right which stands in for ‘the cat’s’ and indicates ownership.
It’s an amazing idea.
A missing letter has been replaced by the apostrophe, so it really means ‘it is’:
Whose/who’s
Whose shoes are they?
Here whose is a special kind of pronoun (like its) which indicates ownership already, so there is no apostrophe.
Who’s coming to dinner?
A missing letter has been replaced by the apostrophe, so it really means, ‘who is’.
Dates
The 1960s were a period of radical changes in morality.
In the ’60s, public morality underwent radical changes.
1960s’ morality was quite different to that which had gone before.
– In the first sentence, ‘1960s’ is a plural referring to all the years between 1960 and 1969, so there is no apostrophe.
– In the second sentence there is a contraction with ’19’ missed off. The apostrophe replaces the missing numbers.
– In the third sentence, what is being referred to is the morality of the 1960s, so the apostrophe indicates possession.
It is worth remembering that words may end with ‘s’ because they are plurals, and not because they indicate ownership or contraction. Look at what the word is doing and apply an apostrophe only if appropriate.