Commas

Learn about commas, why they are important, and the different ways they can be used.

Introduction

Commas are the most commonly used punctuation mark. They indicate a pause.

In this lesson, we will look at the different instances in which we should and should not use commas. Please note that you may come across technical jargon in this chapter. If a term is unclear, or for a discussion on the various parts of speech, please have a look at the “Appendix A. Parts of Speech (Recommended for ESL Writers)” chapter.

Quick tip: Read these examples aloud to hear the pauses created by the commas. A comma represents a 1/2 second pause.

How to use commas with a series

The Oxford comma (also known as the serial comma) is the last comma in a list of items.

  • Example → “At the store I bought bread, milk, and eggs.”

In this sentence, the Oxford comma is the comma right after “milk.”

This rule for commas generates a lot of debate. Some style guides argue that it is unnecessary, whereas others dictate that is it crucial to use the Oxford comma.

Note: Always check with your professor, employer, publisher, or style guide to see if the Oxford comma is required. If it is unclear, the choice is up to you.

Let’s take a look at how the Oxford comma is used.

  • Incorrect → “Let’s invite Mary Jane, Samuel, Fredrick and Sara to the party.”

  • Correct → “Let’s invite Mary, Jane, Samuel, Fredrick, and Sara to the party.”

The Oxford comma rule says to place a comma before the word “and” in a series.

How to use commas with compound sentences

We can use commas to join two independent ...