Rule 1: Introducing a List
Use a colon to introduce a list after an independent clause.
Example: I fear various supernatural creatures: ghosts, goblins, boogie men, and vampires.
Note- Never use a colon after a linking verb (is, are, was, were, feel, seem, become), after a preposition, or after "such as," "like," or "for example."
In each of these cases, no colon is necessary. Simply go on with the sentence without it.
Rule 2: Introducing a Quotation
Use a colon to introduce a quotation after an independent clause.
Example: John Milton had a lofty aim for his Paradise Lost: "To justifie the ways of God."
Exercise
1. I wished for: candy, a new bicycle, books, a whistle, and a supermodel.
for candy correct
2. To her, the ink blot looked like: an elephant, two runners crossing the finish line, or Elvis having a hot fudge sundae in Central Park.
like an elephant, correct
3. The grocery list contained only a few items, corn, carrots, and Sulfuric acid.
items: correct
4. In actuality, the party was not fun; it was: boring, overcrowded, overpriced, and smelly.
was boring, correct
5. The following chores are on the "to do" list: shopping, gardening, mopping, washing dishes, doing laundry, and mailing bills.
list shopping correct
Answers
1. for candy (a colon cannot interrupt a preposition phrase)
2. like an elephant, (a colon cannot interrupt a dependent clause)
3. items: (a colon introduces a list following an independent clause)
4. was boring, (a colon cannot disrupt a linking verb)
5. correct (the colon introduces a list following the independent clause)