This document provides guidelines for using commas including: using commas to separate independent clauses joined by conjunctions; placing commas after introductory clauses, phrases, or words; using commas in a series of three or more items; separating coordinate adjectives with commas; and setting off phrases at the end of a sentence that refer back to the beginning or middle. It also discusses using commas with quotations, dates, places, and to prevent confusion.

1. Guide to Commas
Andrew O’Leary

2. Use commas to separate independent
clauses when they are joined by any of
the 7 conjunctions
 But
 For
 Nor
 So
 Yet
• Yesterday was her brother's birthday, so
she took him out to dinner.

3. Use commas after introductory
 Clauses
 Phrases
 Words that come before the main
clause.
• Because he kept barking insistently, we
threw the ball for Smokey.

4. Do not use commas to set off
essential elements of the sentence
 The person checking tickets at the
counter asked for a form of
identification.

5. Use commas to three or more words,
phrases, or clauses written in a series
 When the snow stops falling, we'll
shovel the driveway.

6. Use commas to separate two or more
coordinate adjectives that describe the
same noun.
 Your cousin has an easy, happy
smile.

7. Use commas near the end of the sentence
to separate contrasted coordinate elements
or to indicate a distinct pause or shift
 The chimpanzee seemed reflective,
almost human.

8. Use commas to set off phrases at the end of
a sentence that refers back to the beginning
or middle of a sentence
 Nancy waved enthusiastically at the
docking ship, laughing joyously.

9. Geographic names and dates
 Birmingham, Alabama, gets its name
from Birmingham, England.
 July 22, 1959, was a momentous day
in his life.

10. Use commas to shift between the
main discourse and a quotation
 John said without emotion, "I'll see
you tomorrow."
 "I was able," she answered, "to
complete the assignment."
 In 1848, Marx wrote, "Workers of the
world, unite!"

11. Use commas necessary to prevent
possible confusion
 To George, Harrison had been a sort
of idol.