Both Petrarchan and Shakespearean sonnets initially enjoyed popularity in 16th-century England, and both forms have been appropriated by English writers throughout the centuries since. While both kinds of sonnets have 14 lines and are written in iambic pentameter, they differ notably in their form and focus.
The Petrarchan sonnet was innovated by its namesake, Francesco Petrarch, a 14th-century Italian poet. Its 14 lines fall into two main divisions: the first eight lines, or “octave,” and the final six lines, or “sestet.” The octave involves only two rhymes, with a scheme of ABBA ABBA. The sestet’s rhyme scheme varies, but it involves either two or three rhymes in patterns such as CDECDE and CDCCDC. Its early English composers included Sir Thomas Wyatt and Henry Howard, Earl of Surrey.
Petrarchan sonnets are traditionally written from the point of view of a man longing for a woman to return his love. The sonnet sets up a problem or describes an incident in its octave, then resolves it or reflects on it in the sestet. The shift in tone between the octave and sestet is called the “turn” or “volta.” Thomas Wyatt’s famous sonnet that begins “The long love that in my thought I harbor” exemplifies this model. Its octave describes the speaker’s love, long hidden in his heart, becoming visible in his face. The woman he loves “takes displeasure” in this display of affection, wanting “reason, shame, and reverence” from him instead of an overt demonstration of love. In the sestet, then, love “fleeth” to “the heart’s forest”; the chastened speaker retains his feelings, but no longer displays them.
The Shakespearean sonnet, also known as the English sonnet, was innovated by the Earl of Surrey and his contemporaries, but since Shakespeare wrote prolifically and well in the form, later readers named it after him. Its 14 lines are divided into three quatrains, or four-line units, and one couplet. The quatrains rhyme ABAB CDCD EFEF, with the final couplet rhyming GG.
Shakespearean sonnets commonly use the three quatrains to reflect on a given situation in slightly different ways, although they do sometimes follow the Petrarchan octave-sestet division of material instead. The final couplet often exhibits a turn or volta containing a shift in perspective, or makes a witty comment about the foregoing material. For instance, Shakespeare’s famous Sonnet 60 begins, “Like as the waves make to the pebbled shore, / So do our minutes hasten to their end.” Its first quatrain establishes time’s endless turnover, with moments forever passing; its second quatrain casts that endless march in terms of human aging; the third quatrain further personifies time as a hungry reaper. The final couplet counters the melancholy mood of these observations by presenting poetry as a foil to time: “And yet to times in hope my verse shall stand, / Praising thy worth, despite his cruel hand.”