A comma is a punctuation mark that represents a short pause and is used to divide parts of a sentence. It has the same shape as an apostrophe or single closing quotation mark in many typefaces, but it differs from them in being placed on the baseline of the text. Commas are used in many contexts and languages, mainly to separate parts of a sentence such as clauses, and items in lists mainly when there are three or more items listed. Some of the most common uses of commas include:
- Separating items in a list of three or more.
- Connecting two independent clauses with a coordinating conjunction.
- Setting apart non-restrictive relative clauses.
- Setting apart nonessential appositives.
- Setting apart introductory phrases.
- Setting apart interrupters and parenthetical elements.
- Setting apart question tags.
- Setting apart names in direct address.
- Separating parts of a date.
While commas are versatile and have many different uses, they can also be the cause of many grammatical mistakes.
