

The next quatrain explains the problem or provides an exposition to the reader. The octave introduces a problem or conflict in the mind of the speaker, in the first four lines (known as the first quatrain). However, in Italian sonnets in English, this rule is not always observed, and CDDCEE and CDCDEE are also used. In a strict Petrarchan sonnet, the sestet does not end with a couplet, since this would tend to divide the sestet into a quatrain and a couplet. For background on the pre-English sonnet, see Robert Canary's web page, The Continental Origins of the Sonnet. This form was used in the earliest English sonnets by Wyatt and others.

Some other possibilities for the sestet include CDDCDD, CDDECE, or CDDCCD (as in Wordsworth's "Nuns Fret Not at Their Convent's Narrow Room," a sonnet about sonnets). Petrarch typically used CDECDE or CDCDCD for the sestet. The rhyme scheme for the octave is typically ABBAABBA.

The original Italian sonnet form consists of a total of fourteen hendecasyllabic lines (in English sonnets, iambic pentameter is used ) in two parts, the first part being an octave and the second being a sestet. Because of the structure of Italian, the rhyme scheme of the Petrarchan sonnet is more easily fulfilled in that language than in English. The Petrarchan sonnet, also known as the Italian sonnet, is a sonnet named after the Italian poet Francesco Petrarca, although it was not developed by Petrarch himself, but rather by a string of Renaissance poets.
