What is alliteration?

In alliteration, consonant sounds in two or more neighboring words or syllables are repeated. The repeated sounds are usually the first, or initial, sounds—as in "seven sisters"—but repetition of sounds in non-initial stressed, or accented, syllables is also common: "appear and report." Alliteration is a common feature in poetry, but it is also found in songs and raps and speeches and other kinds of writing, as well as in frequently used phrases, such as "pretty as a picture" and "dead as a doornail."

Alliteration can in its simplest form reinforce one or two consonant sounds, as in this line from William Shakespeare's "Sonnet XII":

When I do count the clock that tells the time

A more complex pattern of alliteration can be created when consonants both at the beginning of words and at the beginning of stressed syllables within words are repeated, as in the following line from Percy Bysshe Shelley's "Stanzas Written in Dejection Near Naples":

The City's voice itself is soft like Solitude's

As a poetic device, alliteration is often discussed with assonance, the repetition of stressed vowel sounds within two or more words with different end consonants, as in "stony" and "holy"; and consonance, the repetition of end or medial consonants, as in "stroke" and "luck."