Punctuation is necessary to clarify the writer's meaning in a sentence. Punctuation marks are used to indicate a sentence has ended, show the relationships between words and groups of words in a sentence, and set off direct quotations and dialogue. While dialogue formatting is covered in another guide, this document focuses on:
Used to end a sentence, indicating a complete stop.
There was nothing left for us to do, so we left work and went home.
Used at the end of a question that is being asked:
We've finished our work now, may we go home?
It can also be used to show surprise, uncertainty or incredulity:
You mean we can leave work early today?
I wonder if I should try and leave early?
Did you really get to leave work early yesterday?
Used to emphasise something that is strongly felt:
Stop doing that!
Oh no!
Don't ever come near me again!
The exclamation mark should be used sparingly, and only when genuine emotion or feeling needs to be expressed. Overuse will lessen its impact.
The most frequently used form of punctuation. Its main purpose is to break up sentences into smaller, digestible sections without fragmenting it into many short sentences, or to separate groups of words from one another in order to clarify the meaning of a sentence. When proofreading something you have written, place a comma where you instinctively pause; this method will rarely fail you.
The following sentence is confusing as written:
Mr. Smith was thinking of various things for his own benefit as Charley bit his nails while he waited for the answer.
The placement of a comma helps to clarify the meaning of the sentence:
Mr. Smith was thinking of various things for his own benefit, as Charley bit his nails while he waited for the answer.
As it is written, the following sentence is quite confusing:
I'm very good at what I do and amongst other talents, I've polished, I'm very good at crisis management.
Punctuating the sentence helps to clear up any ambiguity:
I'm very good at what I do, and amongst other talents I've polished, I'm very good at crisis management.
A comma is used before a coordinating conjunction such as and, but, or, for, yet, and so:
The trip was long and tiring, for we were delayed by the eruption of the volcano.
We hadn't paid our electricity bill, so the power was cut off.
File your tax form on time, or you'll be faced with a hefty fine!
There is no need to slam the door, but someone always does so.
We are going to Spain for the summer, and plan to stay for three months.
Commas are also placed when using lists.
I went to the Lush Store yesterday to buy a leather whip, steel handcuffs, a massive tub o' lube and a shiny new butt plug.
Note the comma before the last item in the list (before the 'and') is optional. It should be employed if it makes the sentence clearer, otherwise may be omitted.
Another common way to use the comma is to insert sub-sentences which give additional information. This works in a similar way to parentheses without the implication that what is contained within is somehow an aside. When you use the comma in this way, an easy way to check if it is correct is by removing the section between the commas. If the sentence still makes sense then you're fine:
There's nothing, and I mean nothing, better than sleeping alongside the person you love.
When part of a quotation has been omitted, three points are used to indicate that information is missing. This is known as an ellipsis.
We received news from the hotel we were booked into, informing us that: "Your reservation has been verified for the week of.... Please message that our hotel has a full range of services..., and cots can be provided for small children at no extra charge".
When used in dialogue, an ellipsis can indicate a thought that has been interrupted:
"Do you think that we should... oh, never mind. I know you wouldn't be interested anyway."
It can indicate speech that trails off:
"Yes, Brian said he was on his way home," Jane said, "but still, it's been three days…"
Used in order to join two independent statements that are closely related, particularly if the second statement provides additional, specific information that helps to explain or clarify the first one:
You might find it uncomfortable to be back home; your parents have rented your room out to a college student.
Janice was nervous during the flight to Europe; in fact, it was the first time she had ever flown.
It is also used before conjunctive adverbs such as moreover, however, therefore or indeed, that show the relation between the two clauses:
Normally the department store closes at 7 o'clock; however, during the holiday season it will remain open until 9.
The boys didn't respect their curfew Friday night; therefore, they are grounded for the rest of the weekend.
Serves to formally introduce lists of things, quotations, extracts, an explanatory clause, or speeches. These can also be preceded by a comma, but using a colon serves to make it more formal:
When preparing for a trip, the following items are mandatory: passport, tickets, and money.
I wish I knew who first said: "A penny saved is a penny earned", and whether or not he had a lot of savings.
Everything was ready for the dinner party: the food was prepared, the table was set, and the guests had arrived on time.
The President stepped up to the podium and began his speech: "Your Majesties, Your Royal Highnesses, Distinguished Members of the Norwegian Nobel Committee, citizens of America, and citizens of the world:
I receive this honor with deep gratitude and great humility..."
A colon is also used when writing the time of day, to differentiate between an act and a scene from a play, to separate a book's title from its subtitle, and when using Biblical references, in order to separate chapter from verse:
The time is now 8:45
Romeo and Juliet IV:3
"The Professor and the Madman: A Tale of Murder, Insanity, and the Making of the Oxford English Dictionary", was written by Simon Winchester.
The visit of the Magi is recounted in Mathew 2:1-12
Used to show a break of shift of thought:
I was going to explain it to you – but never mind now, you don't seem to be interested.
His reputation should have warned her he wasn't – well, perhaps the less said the better.
If a sentence ends with a dash, the period is omitted:
If you really feel that way –
The dash can be used to increase suspense, as emphasis, or to set off parenthetical information:
They already knew – they had to have known – that the project wasn't likely to obtain approval.
The presentation was up to the standards we expected – indeed, it exceeded our expectations.
The set back is minor, I tell you – truly minor – and the delay won't inconvenience you whatsoever.
The dash can be used to show that letters or words have been omitted:
Reverend M- gave his usual stultifying sermon last Sunday morning.
The Spanish Flu pandemic, 1918-1919, is thought to have been responsible for 50-100 million deaths world wide.
Hyphens are used in order to separate prefixes in certain words, and to connect the parts of some compound words and phrases. Hyphens are used in spelling compound words in order to avoid confusion of meaning:
My coworker called in sick today
is a statement that makes more sense if it is written thus:
My co-worker called in sick today
Hyphenate two nouns that are different, yet equal in terms of the meaning conveyed:
Compound nouns consisting of three or more words are also hyphenated:
The suffixes -designate, -elect, and -odd are hyphenated:
Prefixes that require hyphenation are all-, great-, half-, and self-:
Hyphens are used with proper nouns and adjectives that have prefixes:
When two or more words are joined to form a compound adjective that precedes a noun, the hyphen is used:
However, if the compound adjective follows the noun, it is not hyphenated:
Parenthetical information consists of words or groups of words that interrupt the main structure of the sentence. This information is usually not necessary to the meaning of the sentence, and it is punctuated with either commas, dashes, or parentheses. The use of a dash can be quite dramatic; parentheses serve to isolate the words or phrases, making them seem remotely connected to the sentence:
If you see any strawberries at the market (they have to be available by now, I'm sure), please buy several kilos so I can make jam. We've been told to eat a healthy amount of fruits and vegetables (many of them are reputed to have anti-aging properties), but it's often difficult to find good quality produce at reasonable prices, particularly during the winter months.
An apostrophe is used when words are contracted, in order to signal the absence of one or more letters. A contraction is a shortened form of a word or group of words. Some of the more commonly used contractions are:
The apostrophe is also used to indicate that a noun or an indefinite pronoun is possessive:
An apostrophe is also used when one or more digits in a number are left out:
However, if the date mentioned spans several years, no apostrophe is needed: