Commas
The comma is arguably the most versatile punctuation mark. Since its list of uses is so lengthy, let’s get going!
Lists
If you have a series of three or more things, separate those words with commas.
Wrong: Braeden bought apples bread yoghurt and zucchini at the grocery store.
Right: Breaden bought apples, bread, yoghurt, and zucchini at the grocery store.
In the example, I included a comma before the “and”. This comma is called the Oxford or serial comma, and it is not essential. However, it can eliminate confusion.
Whether or not you use the Oxford comma, it’s important to choose one method and stick with it.
Adjectives
Have you ever noticed that some adjectives had commas between them and others don’t?
Commas: I live in a red, white, and black house.
No Commas: I live in a genuine 18th-century house.
Believe it or not, there actually are rules about when commas go between adjectives and when they don’t. Use commas if your adjectives are coordinate, meaning that the adjectives can go in any order and you can put “and” between them.
Rearranging the Order: I live in a white, black, and red house.
Adding And: I live in a red and white and black house.
Both of those sentences make sense.
Don’t use commas if your adjectives are cummulative, meaning that you can’t rearrange them or put “and” between them.
Rearranging the Order: I live in an 18th-century genuine house.
Adding And: I live in a genuine and 18th-century house.
Huh? These sentences don’t make sense because “genuine” is modifying “18th-century” not “house”. The speaker is saying that his house really is from the 18th-century, not that it’s really a house. Grammar Girl has more examples to help you with this tricky concept.
Quotes
Quotes that occur in the middle of a sentence get lots of introduction. First, there’s a comma, then the quotation marks, then the actual quote. Like this:
After breakfast, Janine said, “I’m stuffed!”
If you’ve got a broken quote, you also need a comma after the first half:
“My concern”, said Jackson, “is that I’ll be late for the bus.”
Parenthetical Elements
A parenthetical element is a phrase or word that is not essential to your sentence and can easily be removed. You indicate that this part of the sentence is parenthetical by setting it off with commas.
Evangeline’s comma splice, usually an egregious offence, was hardly noticed.
Honestly, I rarely go to the movies.
Non-restrictive relative clauses are a type of parenthetical element.
Places and Dates
Separate smaller places from the larger places in which they are located (e.g. cities from provinces, states from countries).
Victoria, British Columbia
Paris, France
New Mexico, USA
If you write dates in the month, day, year format, place a comma between the day and the year:
May 12, 2014
If you write dates in the day, month, year format, don’t use any commas:
12 May 2014
Conjunctions and Dependent Clauses
Using commas with coordinating conjunctions and dependent clauses is covered in the sentences lesson.
Learn More: