When properly placed, commas clarify meaning by helping readers organize information. Without it, sentence parts can collide into one another and cause confusion. However, too many commas can cause distraction.
Rules for comma usage:
- Commas with numbers:
- Don’t use commas in decimals.
- 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 Alexandria, ...
- 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:
- Use a comma after yes and no.
Affirmatives: Yes, I can help you.
Negatives: No, I can't help you.
-Question Tag: Use a comma before question tags.
Positive main clause - Negative question tag
Example: You are Scottish, aren't you?
Negative main clause - Positive question tag
Example: You aren't Scottish, are you?
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.
Example: It was a cold and windy night.
If adjectives give different kinds of information, the and between the adjectives doesn't sound right. (Example of wrong use: 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 sentence 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. (The question mark replaces the comma because it is a question)
12. Commas with interjections:
- Use a comma to separate an interjection or weak exclamation from the rest of the sentence.
Wow, you really did it this time! (Wow is an interjection)
Hey, will you do me a favor? (Hey is a weak exclamation)
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.
Colons have a number of functions:
1. To introduce an idea.
The colon is used to introduce an idea that is an explanation or continuation of the one that comes before the colon. The colon can be considered as a gateway inviting the reader to go on.
You are left with only one option: Press on until you have mastered it.
There is one thing you need to know about coleslaw: it looks and tastes like slurry.
In the above examples you have some idea of what will come after the colon. It is important to note that the clause that comes before the colon can stand alone and make complete sense on its own.
If the initial clause cannot stand alone and make complete sense, you should not use a colon.
2. To introduce a list.
The second main use of the colon is to introduce a list. You need to take care; many people assume that a colon always precedes a list. This is not the case. Again it is important to remember that the clause that precedes the colon must make complete sense on its own.
The potion contained some exotic ingredients: snails’ eyes, bats’ tongues and garlic.
The magic potion contained sesame seeds, bran flakes and coleslaw.
In the first sentence, the clause preceding the colon has a subject and a predicate and makes complete sense on its own 'The potion contained some exotic ingredients.' In the second sentence a colon should not be used, as the clause that would precede it would not make sense alone 'The magic potion contained'.
3. To introduce quoted material.
The colon has other uses: it can also be used after a clause introducing quoted material.
Example: The girl often used her favourite quotation from Romeo and Juliet: “Oh Romeo, Romeo, where art thou Romeo?”
If the colon precedes a quotation, you should begin the language of that quote with a capital letter.
4. For style.
Having mastered the correct use of the colon, it is useful to make it work for you in your writing. Using a colon can add emphasis to an idea. For example, consider the following two sentences:
The one thing mankind cannot live without is hope.
There is one thing that mankind cannot live without: hope.
Both sentences are grammatically correct, but the second makes the point a little more forcefully. Now we are in the realms of style, it is important to emphasize that you, as the writer, have to decide how to make your newfound expertise with punctuation work for you. Do not be tempted to overuse colons. They are powerful but should be used with precision and care.
- Use a semicolon to join two independent clauses. (This eliminates the need for a comma and a conjunction.)
With a comma and conjunction: My grandmother seldom goes to bed this early, because she’s afraid she’ll miss out on something.
With a semicolon: My grandmother seldom goes to be this early; she’s afraid she’ll miss out on something.
2. Use a semicolon to separate items in a series when those items contain punctuation such as a comma.
Example: We went on field trips to Topeka, Kansas; Freedom, Oklahoma; and Amarillo, Texas.
Topeka, Kansas is one place, Freedom, Oklahoma is another place, and Amarillo, Texas is another. The semicolon just makes it easier to tell that these are not all separate places.