Assonance is a literary device that involves the repetition of vowel sounds within nearby words. This technique creates a musical quality in writing, enhancing the rhythm and mood of a poem or prose. For example, in the phrase "The rain in Spain stays mainly in the plain," the repeated "ai" sound draws attention and adds a lyrical touch. Writers often use assonance to evoke emotions or emphasize certain ideas. It can be found in various forms of literature, from poetry to song lyrics. By carefully choosing words with similar vowel sounds, authors can create a more engaging and memorable experience for their readers.