John Keats fills his poem "On the Grasshopper and Cricket" with delightful poetic devices that hold readers' attention and give depth and interest to the poem.

He begins with a metaphor that extends throughout the poem: the "Poetry of earth." This poetry refers to the sounds of nature, the songs of the birds and grasshoppers and crickets. These have a beauty that compares to poetry, Keats asserts.

The birds and insects are also personified in this poem (i.e., given human characteristics and actions). The birds grow faint in the heat and hide in the trees. The grasshopper "takes the lead" in the song or poetry of nature. He delights in the fun he has during the hot days and then rests in the weeds when he gets tired. The cricket sings in the winter to continue the poetry and music. Even the frost is personified, as it "Has wrought a silence" in the winter.

Notice, too, the vivid sensory details Keats provides. We can picture the "cooling trees" and the "new-mown mead" as well as the "summer luxury" and the "lone winter evening" in which someone dozes near the fire.

Keats adds some linguistic fun as well with alliteration in phrases like "new-mown mead" (the repetition of m) and lines like "Has wrought a silence, from the stove there shrills" (with its s alliteration). He even incorporates synecdoche (in which a part represents the whole) when he speaks of a voice running through the hedges. This voice stands for the whole grasshopper, but it is a fitting device, for we hear the little insect rather than see it.

A great example of a poetic device used by Keats in "On the Grasshopper and Cricket" is the metaphor in the very first line: "The Poetry of earth is never dead."

Literally speaking, there is no poetry in the earth; poetry is a creation of human beings like Keats. But in metaphorical terms, the earth is indeed jam-packed with poetry, whether it comes in the form of the cricket's song or the grasshopper's voice.

Nature speaks all year round, whether in the heat of summer or the cold of winter. And this constant speaking constitutes the poetry of the earth that is never dead and never ceases.

Keats resorts to the poetic device of personification to drive home his point about the poetic nature of the earth. He describes the voice of the grasshopper running "From hedge to hedge about the new-mown mead." Of course, a voice cannot literally run. But in figurative terms, it most certainly can. And here, the voice of a grasshopper runs from hedge to hedge in much the same way that an excited child would in the summertime.

We are told that the grasshopper is "tired out with fun." This is another example of personification, as grasshoppers don't honor us with their voices for fun, as humans do, but because it's in their nature to do so.

In the opening line of the poem, Keats uses metonymy when he writes that "The Poetry of the earth is never dead." Metonymy is a poetic device whereby the name of something is replaced by a different word that represents that same something in a symbolic way. In the example in the opening line of this poem, the word poetry is used as a replacement for the word life. The meaning of the line is that the life of the earth never dies, but by using the word poetry instead of life, Keats suggests that that life is beautiful, musical, intricate, and creative.

Throughout the poem, Keats uses juxtaposition to emphasize the point that the life or "poetry" of the earth continues at all times, through all seasons and climates. For example, in the second and third lines of the poem, Keats says that this life endures during "the hot sun" as well as in the "cooling trees." Later in the poem, he writes that the life of the earth endures "in summer luxury" and also in "lone winter evening[s]." The juxtaposition here emphasizes how robust and indefatigable is the life that pulses through the earth.

To further emphasize the same point, Keats also uses repetition. For example, he says that the pulse of life will "run/ From hedge to hedge," and he also uses the word never three times in the poem. In the first line, he writes that the life of the earth is "never dead"; in the sixth line, he writes that this life is "never done"; and in the ninth line, he says that it is "ceasing never."

Poetic devices are the same as literary devices plus the addition of some structural features that are specific to poetry. Some structural features follow: "On the Grasshopper and the Cricket" is a fourteen line sonnet with a rhyme scheme of a b b a a b b a  c d e c d e with no end couplet making it a Petrarchan sonnet instead of a Shakespearean sonnet.

The rhythm is in iambs ( ^ / ) for five feet of repeating patterns: it is in iambic pentameter. The sonnet structure is an octave of eight non-alternating lines and six ending lines comprising a sestet. There are voltas (turns in topic) at lines 5 and 9 where the topics turn from the general voice of the poetry of nature to the specific voice of the grasshopper (5) and the from the grasshopper to a comparison of the cricket in winter to the grasshopper of summer.

Some poetic devices classed as techniques used by Keats follow: The poem is based upon a double metaphor in which the poetry of earth is compare to the grasshopper and the cricket is compared to the grasshopper. Keats also employs personification (e.g., "he rests at ease," "frost has wrought") and sensory imagery (e.g., "voice will run from hedge to hedge").

Keats also uses the figures of speech that are word schemes, which manipulate sounds, letters, syntax and words to create rhetorical effects. He uses anastrophe, a type of hyperbaton, that places the adjective on the wrong side of the noun (e.g., "ceasing never," "warmth increasing ever"). He also uses the type of hyperbaton called apocope in which the word-final letters or syllables are dropped for effect or to fit a meter. An example is "lone winter evening" in which the -ly is dropped from lonely to create lone.