Comma-Then is not an actual grammar structure—not by name anyway. It’s a phrase titled for a pet peeve of author Jonathan Franzen.
In his blog post, “Comma-Then,” he describes a syntax pattern that he names the “comma-then” structure, suggests its use is incorrect, and offers three examples to illustrate his point.
1. She lit a Camel Light, then dragged deeply.
2. He dims the lamp and opens the window, then pulls the body inside.