Carnegie Mellon University

Grammar Tips: Commas

Commas help guide readers through the work that you write, but the “rules” often depend on your purpose. While these guidelines won’t apply to every scenario, they can serve as guidelines that help you consider how readers will interpret your ideas.

This handout explains how commas:

  • Signal the beginning of a thought;
  • Indicate a direction change;
  • Separate essential and nonessential information;
  • Distinguish complete statements.

To get started editing your sentences, click the link in the sidebar to view, download, and print the PDF.

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