Assonance — Literary device · Learn · Poets of The Household

Mechanism

Assonance repeats the same vowel sound in the stressed syllables of nearby words: the deep green sea, a lone road home, bright light in the night. The consonants around the vowels can differ — what matters is that the vowel itself returns, and that the ear catches it.

As with alliteration, the technical definition is narrow: the assonance has to land in stressed positions, and the words have to be close enough that the repeated vowel registers. Two words five lines apart with the same vowel do not assonate audibly; two stressed vowels in adjacent feet do.

Impact

Assonance gives a line its vowel-music. Because vowels are sustained sounds — they can be drawn out — assonance tends to slow a line and lengthen it on the ear, where alliteration tightens and binds. Many lyric poems whose appeal is hard to name on the page turn out, on close reading, to be carrying their charge in the vowels.

It also colours the line emotionally in ways the consonants alone cannot. Long open vowels (/o/, /a/, /ee/) tend to feel ceremonial, mournful, or extended; short closed vowels (/i/, /u/) tend to feel tight, anxious, quickened. A poet's choice of which vowel to assonate on shapes the line's affective temperature as much as the choice of which word to use.

In real lines

Thou still unravish'd bride of quietness, Thou foster-child of silence and slow time, Sylvan historian, who canst thus express A flowery tale more sweetly than our rhyme:

Sample Poet

Keats's opening quatrain builds on overlapping vowel-chains — /i/ across 'still', 'bride', 'silence', 'time'; /o/ across 'thou', 'foster', 'slow'; /e/ across 'express', 'sweetly'. The assonance carries the stanza under the iambic pentameter without taking over the rhyme.

And the silken, sad, uncertain rustling of each purple curtain Thrilled me—filled me with fantastic terrors never felt before;

Sample Poet

Poe runs assonance on /i/ ('silken', 'thrilled', 'filled') and /u/ ('uncertain', 'rustling', 'curtain', 'purple') through both lines. The vowels — combined with the internal rhymes — give 'The Raven' the hypnotic, hallucinatory pacing that has made it one of the most-quoted assonant poems in English.

Assonance is foundational to lyric poetry across most traditions. Where the alliterative verse of Old English carried lines on consonants, the lyric traditions that succeeded it carried them on vowels: Keats's odes are vowel-music compressed into stanzas, Tennyson's late lyrics build whole stanzas on a single sustained vowel, and the songs of the Romance traditions (French, Italian, Spanish) often rhyme only on the final vowel — assonant rhyme — rather than on the full final syllable.

In Spanish-language poetry assonance is structurally central: classical romance ballads rhyme by vowel alone, and Lorca and Machado built whole bodies of work on assonant rhyme schemes that English readers, accustomed to perfect rhyme, sometimes do not hear as rhyme at all. The device runs through the coplas of Spanish folk tradition and the décimas of the Spanish-American Caribbean.

In English-language verse assonance more often appears as an internal device — a vowel chain running through a line without taking over the rhyme scheme. Keats's "Thou foster-child of silence and slow time" runs /o/ and /i/ across the line under the iambic pentameter; Poe's "The raven, sitting lonely on the placid bust, spoke only / That one word" assonates on /o/ until the vowel itself feels like the speaker's grief.

Considerations

Many poets find that the trickiest discipline with assonance is restraint. Vowel-music piled too thickly — every stressed syllable for several lines all on the same vowel — can tip into chant or doggerel. A common trade-off is between sustaining a vowel long enough for the reader to hear it and letting other vowels back in before the line monotones.

Another consideration is the difference between assonance the reader hears and assonance the poet hears. The poet, who has the line in their head, sometimes notices vowel repetitions that the reader, scanning naturally, does not register. Reading aloud is often the only reliable test — if the vowel does not arrive on the breath, it is not on the page.

Finally, assonance interacts with rhyme. In a heavily rhymed poem, internal assonance can either reinforce the rhyme scheme or work as a counter-melody against it. Neither is wrong, but the two effects are different, and a poet who has not decided which one they want often produces a line that does both indifferently.

Try this

Take a single line of your own — any line, in any meter — and rewrite it three times, each time concentrating on a different vowel sound in the stressed positions. Read all four versions aloud. Keep the one whose vowel-music does the work the meaning needed.

Each rewrite must keep the same essential meaning as the original.
Each rewrite must place the chosen vowel in at least two stressed syllables.
No two rewrites may use the same vowel chain.

Share your poem

Mechanism

Impact

In real lines

Try this

Further reading