Final answer:
The sentence 'The long, sheer curtains twirled in the breeze' uses personification as its form of figurative language, attributing human-like action to the curtains.
Step-by-step explanation:
In the sentence “The long, sheer curtains twirled in the breeze,” the type of figurative language used is personification. Personification is a figure of speech where human qualities or abilities are attributed to non-human entities. By saying that the curtains “twirl” in the breeze, the curtains are given an action commonly associated with a living being, as if they are dancing. This is different from a metaphor, which makes a direct comparison between two unlike things without using “as” or “like,” and alliteration, which is the repetition of the initial consonant sounds of words in close succession.