In writing, a colon can introduce a quotation without needing a comma if the introductory words form a complete sentence.
When a colon is used to introduce a quotation in writing, the comma can be omitted when the introductory words form a complete sentence. This structure ensures that the colon emphasizes the quotation, offering it added importance. For example, Mark Twain said it best: "When in doubt, tell the truth."
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