The Dash
The dash is a punctuation mark (-)which is used especially to indicate a break in the thought or structure of a sentence.
Examples:
You are the friend—the only friend—who offered to help me.
Never have I met such a lovely person—before you.
I pay the bills—she has all the fun. (A semicolon would be used here in formal writing.)
I need three items at the store—dog food, vegetarian chili, and cheddar
cheese. (Remember, a colon would be used here in formal writing.)