In using a colon to introduce a quotation, be sure the clause before the colon is a complete sentence (can stand alone). Which sentence below uses a colon correctly? A. My teacher's favorite Shakespeare quote is: "To be or not to be -- that is the question." B. My teacher is always quoting Shakespeare when he says: "To be or not to be - that is the question." C. My teacher is always quoting Shakespeare: "To be or not to be -- that is the question."