Learning to speak English real good

A teacher wanted her two students to describe a man who, in the past, had suffered from a cold.

O'Neil said, "The man had a cold," which the teacher said was incorrect.

Debb said, "The man had had a cold," which the teacher was pleased with.

So, in conclusion,
Debb, while O'Neil had had "had," had had "had had," "had had" had had a much better effect on the teacher.