how to use commas

What Are The 3 Main Comma Rules?

The comma is one of the most used punctuation marks in English and helps to clarify the meaning of sentences by indicating pauses, separating ideas, or organizing list items.

However, its misuse can lead to confusion or misinterpretation of the message you are trying to convey. To make sure that you have clarity and precision in your writing, it’s crucial to understand and apply the following three main comma rules effectively.

1. Use Commas to Separate Independent Clauses Joined by Coordinating Conjunctions

When two independent clauses (clauses that can stand alone as separate sentences) are joined by one of the seven coordinating conjunctions (for, and, nor, but, or, yet, so), a comma should precede the conjunction. This rule is pivotal for linking two related but distinct ideas in a single sentence without causing confusion.

Example: “I wanted to go for a walk, but it started to rain.”

Without the comma, the sentence might run together, making it harder for the reader to quickly grasp the point where one idea ends and the next one begins.

2. Use Commas After Introductory Words, Phrases, or Clauses


An introductory element can be a word, a phrase, or a clause that precedes the main clause of the sentence. Commas after introductory elements are essential because they help the reader understand the background or setting before encountering the main statement.


  • Word: “Unfortunately, the event was canceled.”
  • Phrase: “In the early morning, the city looks serene.”
  • Clause: “Although it was raining, we decided to go hiking.”

The comma sets the stage for the main action, ensuring a smoother transition from the introduction to the main point.

3. Use Commas to Separate Items in a Series

When listing three or more items in a series, commas are used to separate each item. This rule prevents confusion, ensuring that the list is easy to read and understand.

The Oxford comma, which is the comma before the conjunction in a list, is optional but can sometimes help avoid ambiguity.

Example without Oxford comma: “I need to buy eggs, milk and bread.”

Example with Oxford comma: “I need to buy eggs, milk, and bread.”

The presence or absence of the Oxford comma can change the meaning of a sentence, so its use often depends on the writer’s preference or the style guide being followed.


Mastering the use of commas according to these three main rules can significantly improve the clarity and readability of your writing. It helps in effectively conveying your thoughts and ensuring that readers understand your message as you intended. Remember, the goal of punctuation is to serve as a guide for readers, not to confuse them. Practice these rules in your writing, and you’ll find that your sentences become clearer and more polished.

Cara Secrist
Latest posts by Cara Secrist (see all)


Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.