Correcting Unclear Pronouns

When you use a pronoun, be sure the reader knows who or what the pronoun refers to. Two possible antecedents can create confusion.
Unclear: When Dakota tried to balance the book on the stack, it fell.
(What does the pronoun it refer to—the book or the stack?)
Clear: The book fell when Dakota tried to balance it on top of the stack.
Unclear pronouns can be humorous.
Unclear: Dakota needed to find Hamlet, in which the Prince of Denmark plotted revenge because he had to write a paper.