Metaphors will often only involve one or two comparisons, while extended metaphors can cover pages or even entire stories.
Metaphors are simple comparisons. They only compare a few things at a time:
“She was their light, their sun, their sky.”
Here, the woman is being compared to three things. But it is only a simple metaphor because it doesn’t go on for too long.
Extended metaphors compare the same thing repetitively over a few lines, pages, or even whole stories. Example:
“Bobby Holloway says my imagination is a three-hundred-ring circus. Currently I was in ring two hundred and ninety-nine, with elephants dancing and clowns cart wheeling and tigers leaping through rings of fire. The time had come to step back, leave the main tent, go buy some popcorn and a Coke, bliss out, cool down.” (Dean Koontz, Seize the Night. Bantam, 1999)
Here, Koontz is comparing his imagination to a circus. However, he uses multiple sentences to do so.
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