Guide on Comma Rules

Introduction

Commas are more than just pauses in a sentence; they're essential for clear communication.
Proper comma use helps avoid confusion.

Separate Items in a Series or List
- Example: "The author thanked his parents, Stephen King, and God."
- Oxford comma (before "and") is optional but can clarify meaning.
- Without it, items can be misinterpreted (e.g., "his parents become Stephen King and God").
Divide a Compound Sentence
- Example: "My mother enjoys sewing, but she doesn't do it often."
- Common error: comma splice (using a comma without a conjunction).
- Without a conjunction, use a period or semicolon.
Set Off Introductory Elements
- Example: "Until you speak to him, don't jump to conclusions."
Set Off Parenthetical or Non-essential Elements
- Example: "The Memorial Bridge, which stands on the north end of town, was finished last year."
- Commas surround non-essential information; sentence remains complete without it.
Separate Coordinate Adjectives
- Example: "The tall, distinguished, handsome man waited in the airport."
- Coordinate adjectives can have "and" inserted between them.
- Non-coordinate adjectives (e.g., "the little old lady") do not use commas.
Set Off Quoted Elements
- Example: "I don't know," said Lou, "do you?"
- Use a comma after a signal phrase in a blended quote.
- Example: "The author insists, we have a moral responsibility to each other."
Separate Dates, Cities/States, and Names/Titles
- Example: "I visited my doctor, Sarah Williams, MD, in Detroit, Michigan, on July 19th, 2023."
- Commas separate names from titles, cities from states, dates from years.