What Do Commas Do?
I have been receiving quite a few questions about the basic purpose of the comma. For example, one Twitter follower asked simply, “Can you explain what commas are for?”
Twitter isn’t really the place for lengthy discussions, so I responded “Commas are used to separate meaningful units in sentences.” Here’s a more lengthy response about the value of commas and how they are used, taken from the introductory sections of Zen Comma.
Commas are confusing
The final stage of the writing process is proofreading: correcting any errors in spelling, punctuation, word usage, and format. Roughly 75% of what I do while proofreading clients’ documents is correct commas.
When I teach community writing courses at the university, I ask the students, “What’s the number one thing that confuses you about punctuation and grammar?” In every class, someone says “Commas,” and about half of the students nod in agreement.
Commas confuse most people. Unlike other types of punctuation, they are used in so many ways. The purpose of this book is to show you how to use them correctly.
If you want to write clearly and professionally, you need to use commas correctly.
What commas do
Commas are visual clues that have only one purpose: Help the reader separate parts of sentences into discrete, meaningful messages.
A sentence may have multiple parts. Each part has some meaning that we are trying to communicate. We combine those parts to write a sentence that has a single message. In most cases, we identify those parts by separating them with commas. This helps the reader find them and understand the overall message of the sentence.
And that, ultimately, is why we use commas: Help the readers understand the ideas we want to communicate.
Do commas matter? Yes!
As you will see throughout this book, where we put the commas, and where we leave them out, can change the meaning of a sentence.
When we’re writing, we already know what we want to say. The reader doesn’t. Our job, therefore, is to help the reader understand our meaning.
And that means the commas have to be right.