When should you not use a comma?

Answer 1

This is a short list of when a comma is not necessary and you should not include a comma in these writing situations:

1. Willy-nilly without following any grammatical or sentence structure rules.
2. When you have not taken the time to learn the rules for using commas.
3. Whenever you want or think you've not used enough commas
4. When you haven't noticed how textbooks and writers use commas as examples of when to use them.
5. Inserting, a comma, after, every few, words.
6. When joining two nouns with 'and' for a compound subject: John, and Mary, ran track.
7. When joining 2 simple sentences or clauses with 'and': We talked, and told jokes.
8. When combining 2 items but you do not have a list of items.
9. When you do not need to naturally take a breath in a sentence.
10. When erroneously trying to make a run-on sentence seem like it should be an acceptable sentence.

Times you might need a comma include:

1. When using a list of three or more items: apples, Oranges, and grapes
2. When joining several persons as a subject: Mary, John, Sally, and Mike formed one team.
3. When properly joining two full complete but different thoughts: We went ice skating, and then we went to eat.
4. After a clause that does not make a complete thought: When he studied, he did well on tests.
5. When quoting a title or text that someone else wrote and they used commas, even if they used them inappropriately.
6. In dialogue to separate the dialogue from the speaker: "Hello, I'm Amy," she said, flashing a broad smile.
7. To separate additional information such as in the above sentence: ...she said, flashing a broad smile.
8. After a salutation in a letter, or closing to a letter: Dear Mom, (your letter)... (signed) Your son, ...
9. (There may be other instances that I've not listed here.)

Learning when to use commas requires learning the rules for commas, paying attention to when other writers use commas, and listening to places when you need to breathe when reading a sentence out loud.

Answer 2

When you don't need one. Like in this sentence.

Answer 3

You should not use a comma in a sentence when the two clauses are not independent. For example, you don't need a comma in a sentence where the second part cannot stand alone as a separate sentence.