RULES FOR COMMA USAGE

1.   Commas with numbers:
- Use commas to separate off the thousands, millions and billions in numbers.
Example: 2,460,558
- Don’t use commas in decimals.
Example: $4534.79
- Use a comma before the year if the date is given as follows: month, day, year.
Example: January 11, 2004
- Don’t use a comma if only two elements of the date are given (e.g. month and year).
Example: I was born in August 1989.

2.   Commas with series (lists):
- Use a comma to separate items in an enumeration.
Example: Mrs. B had a dog, a cat, a fish and a pig.
- Don’t use a comma before and if two items are a unit. Ham and eggs as a dish is a unit and should therefore not be separated by a comma.
Example: Mrs. B had soup, ham and eggs, juice, and an apple pie for lunch.
- Don't use a comma if all items in an enumeration are separated by and, or, nor etc.
Example: Mrs. B had a pig and a dog and a cow and a horse.

3.   Commas with Salutations:
- Use a comma if the sentence starts with an address to someone.
Example: John, may I talk to you for a second?
- Use a comma with salutations in private letters.
Example: Dear Julie, ...
- After the greeting, the comma is optional.
Example: Sincerely, or Sincerely

4.   Commas with "please":
- Use a comma if "please" is at the end of a request.
Example: Send me a letter, please.
- Don't use a comma if "please" is at the beginning of a request.
Example: Please send me a letter.

5.   Commas with Affirmatives, Negatives and Question Tags:
Affirmatives: Use a comma after yes and no.
Example: Yes, I can help you.
Negatives: No, I can't help you.
Question Tag: Use a comma before question tags.
Example: You are Scottish, aren't you?
positive main clause - negative question tag
negative main clause - positive question tag

6.   Commas with Adjectives:
- Use a comma if the adjectives are equally important and give similar kinds of information.
Example: It was a cold, windy night.
- Don't use a comma if the adjectives are not equally important or give different kinds of information.
Example: She was a clever young woman.
Note: To check if adjectives give similar kinds of information or not, put and between the adjectives. (It was a cold and windy night.)
If adjectives give different kinds of information, the and between the adjectives doesn't sound right. (She was a clever and young woman.)

7.   Commas with Adverbs:
- Use a comma after certain adverbs: however, in fact, therefore, nevertheless, moreover, furthermore, still, instead, too (meaning 'also').
- If these adverbs appear in the middle of a sentence, they are enclosed in commas.
Example: The boy, however, was very smart.
- The comma is optional for the following adverbs: then, so, yet.
Example: Then, she ran upstairs. Then she ran upstairs.

8.   Commas between Main Clauses:
- Use a comma between two main clauses which are separated by and or but.
Example: We ran out of fuel, and the nearest gas station was 5 miles away.
- Use a comma to separate parts of a sentences in a sequence. Example: She ran down the stairs, opened the door, saw her mom(,) and gave her a hug.
- Don’t use a comma if these parts of the sentence are separated by and or but.
Example: She ran down the stairs and opened the door and saw her mom and gave her a hug.

9.   Commas with Conditional Sentences:
- Use a comma if the if clause is at the beginning of a sentence.
Example: If I go to London, I will visit the Tower.
- Don’t use a comma if the if clause is at the end of the sentence.
Example: I will visit the Tower if I go to London.

10. Commas with Introductory Clauses:
Use a comma after introductory infinitive clauses.
Example: To improve her Math, she practiced kwizNET Worksheets every day.
- Use a comma after introductory prepositional clauses. Example: Before he went to New York, he had spent a year in Australia.
- Use a comma after introductory participle clauses.
Example: Having said this, he left the room.

11. Commas with Direct Speech:
- Use a comma after the introductory clause.
Example: She said, ''I was in England last year.''
- If the direct speech is at the beginning of the sentence, put the comma before the final quotation mark. (Don’t use a period here.)
Example: ''I was in England last year,'' she said.
- Don’t use a comma after direct speech if the direct speech ends with a question mark or exclamation mark.
Example:
''Were you in England last year?'' he asked. (but: He asked, “Were you in London last year?”) “Wow!” she replied. (but: She replied, “Wow!”)

12. Commas with interjections:
- Use a comma to separate an interjection or weak exclamation from the rest of the sentence.
Examples:
Wow, you really did it this time!
Hey, will you do me a favor?

13. Commas with Additional Information:
- Use a comma if the additional information is not part of the main statement.
Example: Thank you, ladies and gentlemen, for giving me the opportunity to speak to you today.
- Use a comma in relative clauses before who and which if the information is not essential for the understanding of the sentence.
Example: Her brother, who lives in Chicago, came to see her. She has only one brother. He lives in Chicago and came to see her.
- Don’t use a comma in relative clauses if the information is essential for the understanding of the sentence.
Example: Her brother who lives in Chicago came to see her. She has more than one brother. But she was visited by only one of them–the brother who lives in Chicago.
- Don’t use a comma if the relative clause starts with that.
Example: The book that I’m reading now is interesting.

14.       Commas with Opposites:
- Use a comma with opposites, even if they are separated by and or but.
Example: It was the father, and not the son, who went to the disco every Friday.