William Wordsworth was one of the first-generation Romantic poets, and had a long-standing literary collaboration with Samuel Taylor Coleridge. One of the underlying themes in the work of the Romantic poems was nature, and a return to not only taking care of nature but also extolling its virtues, as can be seen with the title of Wordsworth's poem, "The Butterfly."
One literary device used is personification, where humancharacteristics are attributed to non-human things. In the following section of the poem it is used twice.
What joy awaits you, when the breeze
Hath found you out among the trees,
And calls you forth again!
The first use of personification infers that the butterfly can experience "joy," which is a human emotion, not something an insect would experience. The second use is to give the breeze the characteristic of being able to call to the butterfly, also not something the breeze can do.
Imagery is the use of words, details, that "paint" a picture in the mind of the reader, making what is being described that much more vivid. The speaker describes that the butterfly is even more motionless that the ocean in the dead of winter:
How motionless!—not frozen seas / More motionless!
Some devices used in poetry provide the poem with a more musical sound. These include assonance, consonance and alliteration. Look at the following line:
I know not if you sleep or feed.
In the words "sleep" and "feed" there are two literary devices used. The long "ee" sound is called assonance: the repetition of a vowel sound. The "d" at the end of the words creates consonance, the repetition of a consonant sound.
Finally, a simile is used:
Here lodge as in a sanctuary!
The simile is the comparison of two dissimilar things as if they are the same. The speaker says that the ground, trees and flowers belong to the speaker and his sister, and tells the butterfly to treat them as its sanctuary: a place of safety.