Which punctuation mark indicates a continuation of thought without a full stop in prose?

The dash is used in prose to indicate a continuation of thought, allowing the writer to insert additional information or clarify a point without creating a full stop. It effectively creates a pause that adds emphasis or shifts the sentence's direction, maintaining the flow of the narrative. This punctuation enriches the text by allowing for interruptions or asides that enhance understanding while keeping the overall sentence structure intact.

In contrast, parentheses enclose information that is supplementary but not essential to the main point. While commas can also suggest pauses, they typically indicate brief separations rather than a significant shift in thought. Quotation marks are used specifically for dialogue or quoted material, which does not contribute to a continuous thought in the same way a dash does. Therefore, a dash is the punctuation mark that best indicates an extension of an idea within a sentence.