1. Use comma to indicate a break of pause within a sentence

e.g. Bill Gates, CEO of Microsoft, is the developer of the operating system known as Windows.

2. Use a comma when listing three or more items in a series.

3. Use a comma to separate two or more adjectives describing a noun.

4. Use a comma to separate a larger geographical area from a smaller one located within it.

5. Use a comma to separate an introductory phrase from the rest of the sentence.

e.g. After the show, John and I went out to dinner.

6. Use a comma to separate two independent clauses

7. Ryan went to the beach yesterday, but he forgot his sunscreen.

Having two independent clauses in a sentence simply means that you could split the sentence into two shorter sentences while preserving the original meaning. If your sentence contains two independent clauses that are separated by a conjunction (such as and, as, but, for, nor, so, or yet), place a comma before the conjunction.

e.g.Ryan went to the beach yesterday, but he forgot his sunscreen.

8. Use a comma when making a direct address

Amber, could you come here for a moment?

9. Use a comma to separate a direct quotation from the sentence introducing it