Colon after the salutation in a formal letter
Dear Sir or Madam:
Colon to indicate hours and minutes
5:30 p.m.
Colon to show proportions
The ratio of women to men was 2:1.
Colon between a title and subtitle
The Glory of Hera: Greek Mythology and the Greek Family
Colon between city and publisher in bibliographic entries
Boston: Bedford, 2008
Colon to divide chapter and verse in biblical references
Luke 2:14
NOTE:The Modern Language Association (MLA) recommends a period instead of a colon (Luke 2.14).
Exercise: The colon, the semicolon, and the comma