“What about milk?” Debbie asked. Mark reached for the milk. “Let me see.” He shook the carton. “There’s only a drop left.” “I’ll add it to the list.”
This paragraph includes several mistakes.
The paragraph starts with Debbie’s dialogue. Then, it moves to Mark’s. Then, it returns to Debbie’s. We need to start new paragraphs with each new speaker.
And we need to make sure that information about Debbie is alongside her dialogue, and information about Mark is placed alongside his dialogue.
When we put this into action we get this:
“What about milk?” Debbie asked.
Mark reached for the milk. “Let me see.” He shook the carton. “There’s only a drop left.”
“I’ll add it to the list.”
Now that’s perfect.