Comma
The comma is a punctuation mark used to separate information within a sentence. Commas are used to separate the following:
Three or more items in a list
The recipe called for flour, eggs, and butter.
Complete thoughts joined by a coordinating conjunction
I went to the park, but John stayed home.
A dependent clause from an independent clause
Because it was raining, I decided not to go to the beach.
A complete thought from its introduction
Without proper guidance, children are likely to misbehave.
Non-essential information
The Citadel, a Halifax military landmark, has never been attacked.
Colon
A colon is a punctuation mark that is used after an independent clause to introduce information. It is most commonly used to introduce the following:
Lists
The recipe called for the following ingredients: flour, eggs, and butter.
Quotations
The academic calendar is clear on what constitutes plagiarism: “The presentation of words, ideas or techniques of another as one's own.”
Appositives
I know just how to pass this test: study hard.
Semicolon
A semicolon is a punctuation mark used for the following purposes (and only these purposes):
To emphasize the relationship between closely related independent clauses
Public transportation is vital to city life; many people take the bus to work or school.
To separate items in complex lists
The family business team consists of Fred Harvey, president and father; Ruth Harvey, treasurer and mother; and Jack and John Harvey, salespeople and sons.
Semicolons should not be used in the following situations:
To separate an independent clause from a dependent clause
To separate introductory information in a sentence
To start a list
Apostrophe
The apostrophe is a punctuation mark used for the following purposes:
To show possession
Chocolate is Sam’s favorite ice cream flavor.
To indicate letters left out of contractions
Sam doesn’t mind vanilla ice cream.
Single Quotation Marks
Single quotation marks are used to indicate the following:
Key terms or concepts
A ‘gerund’ is a verb ending with -ing that acts as a noun.
A quotation within a quotation
“When I asked the professor how much this assignment was worth he just said ‘Check the syllabus,’ and walked away,” Jill explained.
Double Quotation Marks:
Double quotation marks are used to indicate the following:
Speech or a quotation from a source
Einstein said "Anyone who has never made a mistake has never tried anything new."
As scare quotes to indicate an alternate meaning than the word would normally imply
Politicians say that they “care” about post-secondary student debt.
The title of a poem or a journal article, for example
“Ode on a Grecian Urn” is a poem by John Keats.
In academic writing to indicate information that is from another source
Rosemarie Morgan argues that “Hardy does appear to have had some faith in aesthetic distance” (Morgan 297).
