Many different rhyming forms exist in poetry, some of which include norms that dictate the frequency of rhymes based on location within stanzas and lines. Examples of these forms include sonnets, quatrains, ballads and rhyming couplets.
Like all sonnets, the Petrarchan sonnet consists of 14 lines broken into one eight-line stanza and one six-line stanza. The first stanza typically consists of a rhyme scheme that includes two different rhyming sounds at the end of lines, with the first sound repeated in the first, fourth, fifth and eighth lines. The second sound repeats in the second, third, sixth and seventh lines. The rhyming pattern for the second stanza varies more significantly, with some poems rhyming two sounds across the six lines and others rhyming three sounds. Given language differences between Italian, where the form originated, and English, the form typically is less structured in English poetry.
Different patterns of rhyme include end, eye, identical and broken rhymes. End rhymes, which are the most common type of rhyme, occur when the rhymed sound occurs at the end of two lines in a poem. Eye rhymes occur when two words end with the same series of letters but do not form a rhyme when spoken. An identical rhyme occurs when the same word rhymes with itself. Broken rhymes occur when portions of words, but not the entire words, rhyme.