Sonnet 30 up of fourteen lines in three quatrains and a couplet, rhyming "abab cdcd efef gg". While using the rhyming and metrical structure of the 'English' or 'Surreyan' sonnet, Shakespeare often also reflected the rhetorical form of the Italian form also known as the Petrarchan sonnet. It divides the sonnet into two parts: the "octet" (the first eight lines) usually states and develops the subject, while the "sestet" (the last six lines) winds up to a climax. Thus a change in emphasis, known as the "volta", occurs between the end of the eighth and the beginning of the ninth lines —
Octave (poetry) Octave (poetry) An octave is a verse form consisting of eight lines of iambic pentameter (in English) or of hendecasyllables (in Italian). The most common rhyme scheme for an octave is "abba abba". An octave is the first part of a Petrarchan sonnet, which ends with a contrasting sestet. In traditional Italian sonnets the octave always ends with a conclusion of one idea, giving way to another idea in the sestet. Some English sonnets break that rule, often to striking effect. In Milton's Sonnet 16, the sestet begins early, halfway through the last line of the octave: Patience's too-quick reply