Commas 

Overview

A comma (,) is a punctuation mark that signals a pause, separates ideas, or helps organize sentences so they are clear and easy to read. Using commas correctly prevents confusion and makes your writing more polished.

Separating items in a list

Use commas to separate three or more items in a series.

• Example: I bought apples, bananas, and grapes at the store.

After introductory words or phrases

Place a comma after an introductory word, phrase, or clause at the beginning of a sentence.

• Example: After the game, we went out for pizza.

Before coordinating conjunctions

Use a comma before and, but, or, so, yet, nor, for when they connect two complete sentences.

• Example: I wanted to go to the concert, but the tickets were sold out.

Setting off nonessential information

Use commas around information that adds detail but is not necessary for the main meaning of the sentence.

• Example: My brother, who is in tenth grade, plays the guitar.

With direct address

Use commas when directly speaking to or naming someone in a sentence.

• Example: Sarah, can you help me with my homework?

With dates, addresses, and numbers

Commas separate parts of dates, addresses, and large numbers.

• Example: She was born on July 4, 2008, in Dallas, Texas.

• Example: The stadium holds 50,000 people.

With quotations

In American English, use a comma to introduce or interrupt a quotation.

• Example: He said, “I’ll meet you after school.”

To prevent confusion

Use a comma when leaving it out could confuse the reader.

• Example: Let’s eat, Grandma.

• Not the same as: Let’s eat Grandma.

Summary

Commas help organize sentences, separate ideas, and make writing clear. They are used in lists, after introductions, with quotations, and around extra information. When in doubt, think about whether a pause or separation helps the reader understand your sentence better.