1. Introducing a list:
* Example: We need to buy the following: milk, eggs, bread, and cheese.
2. Introducing a quotation:
* Example: The teacher said: "Please turn in your assignments by Friday."
3. Introducing an explanation or elaboration:
* Example: She had a difficult decision to make: stay in her hometown or move to a new city.
4. Separating the hour from the minute in time:
* Example: The meeting starts at 10:00 AM.
5. Separating a title from a subtitle:
* Example: "The History of the World: Volume 1"
6. After a salutation in a formal letter:
* Example: Dear Mr. Smith:
7. After an introductory phrase or clause in a sentence:
* Example: Here is the solution: use a semicolon instead of a colon.
Important Note: A colon should never be used after a preposition or a verb.