Write Right: All About Commas
If commas make your head whirl when editing, use the tips below to help you add or delete this punctuation from your manuscript. Don't forget to watch for comma splices too!
1. Use commas to separate three or more words, phrases, or clauses written in a series.
He avoids bread, pasta, and cereal in his diet because he is trying to lose ten pounds before Christmas .
2. Use a comma to set off dialogue.
Commas set off the words of the speaker from the rest of the sentence.
"Don't be a jerk," he said, glaring at his brother.
No comma is necessary when reporting rather than repeating a speaker's words.
His brother said that the police showed up at his door after the wild party.
3. Use a comma after most introductory phrases and clauses. (A clause is a group of words that includes a subject and a verb. It functions as an adjective, an adverb, or a noun. A phrase is a group of words in a sentence that does not have a subject and a verb.)
In the living room, he sank onto the chair near the wall of windows.
When a full moon shone high in the sky, the wolf lurked in the shadows by the trees.
4. Use a comma in direct address.
Use a comma to separate the person you're addressing (the noun of direct address) from the rest of the sentence.
Tyler, watch out for the car tailing you!
5. Use a comma between two independent clauses that are joined by coordinating conjunctions—
and, but, for, so, nor, yet and or.
They were strangers, but they made themselves at home.
I stayed on the beach last summer, and I finally learned to waterski.
6. Don't use a comma by itself to separate two independent clauses because it's not strong enough. Instead of
I stayed on the beach last summer, I finally learned to waterski, add a period after the independent clauses to make complete sentences or link them with a comma and coordinating conjunction. This avoids what's called a comma splice.
7. Use a comma with dates.
With dates, use a comma to separate the day from the year.
They are going to Italy on August 9, 2018. No comma is necessary when writing the date with the day followed by the month and the year: 9 August 2018.
8. Use commas to separate adjectives.
When separating two or more adjectives that modify the same noun equally, use a comma.
She covered the bed with an old, tattered blanket. When you're not sure if the adjectives modify equally, switch them around; if the sentence is still clear, the adjectives modify equally.
9. Use commas after greetings and before closings in personal letters.
Use a comma after the greeting in a friendly letter and after the closing in all letters.
Dear Kaitlyn, (greeting) Your friend, (closing)
10. Use commas to set off appositives.
(An appositive is a word or phrase next to another noun and is used to identify or describe the noun.)
Jeff, an avid reader, loves mysteries. The appositive phrase is an avid reader.
11. Use a comma before and/or after an interjection.
Use a comma to separate an interjection from the rest of the sentence.
Hey, will you meet me at the restaurant after work or do you want a lift?
Wow, you sure stood up for yourself!
I told the boss that, yes, I'd come into work early tomorrow morning.
12. Use commas in addresses.
Separate items in addresses with commas. The Centre's address is:
433 Birch Street, Whitefish, ON
13. Use a comma after conjunctive adverbs.
(Working as conjunctions, these are adverbs such as however, finally, indeed, meanwhile, nevertheless, and therefore. They link two sentences and show how they relate.
I forgot to pack a lunch; however, I didn't go hungry as I found last week's bagel in the staff fridge.
I might not be so lucky next time; therefore, I'm going to take the main road to the club.
14. Use commas before and after parenthetical expressions.
On Saturday I went to the farmers' market, where I hadn't been in years, to pick up fresh produce for the dinner party.
15. Use a comma to show you left words out.
Tonight I'll have fish for dinner; tomorrow, beef.
Tonight I'll have fish for dinner, and tomorrow, beef.