At its core, the definition of sonnet in poetry describes a fixed-form poem consisting of fourteen lines, typically written in iambic pentameter. This strict structural framework has served for centuries as a vessel for some of the most intense and concentrated explorations of emotion, philosophy, and beauty in the English language. Unlike free verse, the sonnet operates within a precise architecture, where form and content are inextricably linked, shaping the rhythm and argument of the verse.
The Historical Evolution of the Sonnet
The origins of the sonnet are firmly rooted in 13th-century Italy, where it was known as the "sonetto." Poets like Giacomo da Lentini refined the form, establishing the thematic and structural conventions that would travel across Europe. The form was later adopted and adapted in 16th-century England, where it became a dominant mode of poetic expression during the Elizabethan era. This journey from the Italian courts to the English Renaissance illustrates the sonnet's enduring capacity to convey deep personal reflection within a disciplined structure.
Structural Components and Meter
Understanding the definition of sonnet requires an examination of its two essential structural components: the volume and the division. Every sonnet contains exactly fourteen lines, a quantity that provides the canvas for the poet's argument. Furthermore, these lines are almost always written in iambic pentameter, a metrical pattern featuring five iambs (unstressed-stressed syllable pairs) per line. This rhythmic heartbeat creates the sonnet's characteristic flow, balancing the rigidity of the form with a natural, speaking voice.
The Volta: The Poetic Turn
A crucial element of the definition of sonnet is the presence of the volta, or "turn." This rhetorical shift in thought, argument, or emotional tone typically occurs at the transition between the two main structural divisions. The volta acts as the poem's intellectual or emotional pivot, moving from problem to resolution, question to answer, or tension to release. Recognizing this turn is essential for interpreting the sonnet's final meaning, as it often delivers the insight that the preceding thirteen lines have been building toward.
The Two Major English Forms
When defining the sonnet, it is impossible to ignore the two primary English variants that have shaped literary history: the Shakespearean (or English) sonnet and the Petrarchan (or Italian) sonnet. These forms differ in their division of the fourteen lines and, consequently, in the placement of the volta. While both adhere to the fourteen-line rule, their distinct structures create different rhythmic and thematic experiences for the reader.
Shakespearean Sonnet Structure
The Shakespearean sonnet is organized into three quatrains (four-line stanzas) followed by a final rhyming couplet. Its rhyme scheme is generally ABAB CDCD EFEF GG. This structure encourages a cumulative development of thought, with each quaternion exploring a facet of the poem's central idea. The concluding couplet then provides a concise, powerful summary or twist, often delivering the poem's most memorable line.
Petrarchan Sonnet Structure
In contrast, the Petrarchan sonnet divides its fourteen lines into an octave (eight lines) and a sestet (six lines). The standard rhyme scheme for the octave is ABBAABBA, creating a sense of enclosure and unity. The volta usually occurs between the octave and the sestet, where the problem presented in the first eight lines is responded to, resolved, or reframed in the final six. This form often lends itself to a more contemplative, divided perspective on its subject.
