The Colon

The colon expands on the sentence that precedes it.

• There are many reasons for poor written communication: lack of planning, poor grammar, misuse of punctuation marks and insufficient vocabulary.
• He collected a strange assortment of items: bird's eggs, stamps, bottle tops, string and buttons.
• Peter had an eclectic taste in music: latin, jazz, country and western, pop, blues and classical.

We will often use a colon to separate an independent clause from a quotation (often of a rather formal nature) that the clause introduces:

The acting director often used her favorite quotation from Shakespeare's Tempest: "We are such stuff as dreams are made on; and our little life is rounded with a sleep."