Describe the rules for using commas in a sentence.

The rules for using commas in a sentence are as follows:

1. To separate items in a list: Commas are used to separate three or more items in a series. For example, "I bought apples, oranges, and bananas."

2. To separate independent clauses: When two independent clauses are joined by a coordinating conjunction (such as "and," "but," "or," etc.), a comma is used before the conjunction. For example, "She went to the store, and he stayed at home."

3. To set off introductory elements: Commas are used to separate introductory words, phrases, or clauses from the main part of the sentence. For example, "However, I still managed to finish the project."

4. To set off nonessential information: Commas are used to separate nonessential information or phrases that can be removed from the sentence without changing its meaning. For example, "My sister, who lives in London, is visiting next week."

5. To separate coordinate adjectives: When two or more adjectives equally modify a noun, a comma is used between them. For example, "She has a beautiful, spacious house."

6. To indicate direct address: When directly addressing someone or something, a comma is used to set off the name or title. For example, "John, can you pass me the salt?"

7. To separate contrasting elements: Commas are used to separate contrasting elements or ideas within a sentence. For example, "She was tired, not hungry."

It is important to note that these are general guidelines, and there may be exceptions or additional rules depending on the specific context or style guide being followed.