Punctuation: Semi-colons and Colons

A. Uses of the Semicolon

1. To Connect Two Independent Clauses
• "This could be a complete sentence; this could be another one."
• "Twelve workers started the project; only five remain."
• You usually don't use a semicolon if there's a conjunction between the clauses (and, but, etc.).
2. As a Super-comma
1. We visited Pago Pago, Western Samoa; Curitiba, Brazil; and St. George, Utah.
2. The trio's birthdays are November 10, 1946; December 7, 1947; and October 31, 1950.

B. Uses of The Colon

1. To introduce a list or an enumeration
• This outcome is consistent with the U.S. Supreme Court decisions in three significant cases: Anderson v. Shipowners, United Mineworkers v. Pennington, and Federal Maritime Commission v. Pacific Maritime Association.
2. To expand on the previous statement with a clarifying statement, illustration or result.
• Most of the report consists of hearsay: the statements of others are summarized, quoted, or otherwise relied on.
3. To formally introduce a question
• The Court found that the agreement was invalid: "The owners have limited the activities of the seamen to an extent impermissible by law."
4. For the salutation in a formal letter
• Dear Mr. Lee: