Hyphen (-)
* Purpose: Primarily used to join words or parts of words together to create compound words or phrases.
* Examples:
* Compound adjectives: "well-known," "state-of-the-art"
* Number ranges: "pages 25-30"
* Prefixes: "pre-existing," "anti-inflammatory"
* Word breaks at the end of a line: "The cat- (a pause) erpillar was very hungry."
Comma (,)
* Purpose: Used to separate items in a list, clauses in a sentence, and sometimes introduce phrases or clauses.
* Examples:
* Lists: "I bought apples, oranges, and bananas."
* Compound sentences: "The rain stopped, but the wind continued."
* Introductory phrases: "After the storm, the sun came out."
Dash (—)
* Purpose: Used to indicate a break in thought, a dramatic shift in tone, or to set off a parenthetical phrase.
* Examples:
* Break in thought: "I was about to leave—then I remembered my keys."
* Dramatic emphasis: "The truth is—I don't know."
* Parentheticals: "The meeting—which was scheduled for 10 am—was delayed."
Key Differences:
* Length: Hyphens are the shortest, followed by commas, and then dashes.
* Function: Hyphens mainly connect words, commas separate elements, and dashes create pauses or emphasize.
Remember: The proper use of these punctuation marks depends on the context and the specific rules of grammar. If you're unsure, consult a style guide or grammar resource.