Commas | St. Lawrence University WORD Studio

Commas

Use a comma to separate items in a series.
Please bring your laptop, notes, and textbook to class.

Use a comma before a conjunction that separates two complete, independent ideas. Observe the FAN BOYS: for, and, nor, but, or, yet, so.
I was supposed to do a presentation today, but we ran out of time.
BUT: We were going to discuss that chapter today but didn’t have time.

Use a comma after a dependent, introductory idea (word, phrase, or clause). Notice that these introductory phrases often describe time or place.
As he walked into the ballroom, everyone turned to stare.
Before long, he started to wonder why people were pointing at him.
He’d been in such a rush, he’d forgotten to put on pants.

Use a comma to set off parenthetical or nonessential expressions, those words in a sentence without which the sentence would still have the same meaning.
I went to the ATM, since I didn’t have cash, and found I was overdrawn.

Take heed of “who” or “which” ideas and decide whether the information is essential to the sentence or not:
Chris, who aced the first test, was surprisingly worried about the final.
BUT: The student who aced the first test was the most worried about her grade.

Use a comma to separate date from year and city from state; also use a comma after the city and state if the sentence continues on.
My mother was born in Deadwood, South Dakota, on October 31, 1946.

Use a comma to separate two or more adjectives when “and” could be used between them, or when the adjectives could be switched and retain sense.
It was a hot, dry summer day. - It was a dry, hot summer day.
BUT: She wore a short blue dress.

Use a comma with a direct address or after salutations; also use a comma before titles and degrees following a name.
Hi, Mom! Bye, Mr. Miller, and take care!
Well, that’s a tricky question.
The graduation speaker was John Parker, Ph.D.

Enclose in commas any appositives, words or phrases which rename another word or phrase, or any repeated phrases, or before “too.”
Rudolph, the red-nosed reindeer, had a very shiny nose.
It was glowing, really glowing!
Santa was surprised, too.

Do NOT place a comma between subject and verb. The boys living on the fourth floor of Halls [no comma] came stumbling in late last night. Do NOT place a comma between a verb and its direct object, nor between a direct object and an indirect object.
Don’t forget to give me [no comma] your grammar exercises before you leave.