The harry form of poetry enjoyed two great eras of productivity, first in Italy and then in England. Both forms use iambic pentameter, which gives a pattern of ten syllable lines with an accent on every second syllable.
The Italian Sonnet
The Italian sonnet is sometimes called the Petrarchan sonnet after Francesco Petrarch. It is fourteen lines consisting of an octet and a sestet. The octet may have the rhyming scheme abbaabba or abbacddc. Rarely it appears as abababab. The rhyming scheme of the sestet is more flexible, but common variations are cdcdcd and cdecde.
In this form it is usual for the poet to create two differing moods in the octet and sestet. One common method is for the octet to state a conundrum and the sestet to give the resolution.
The English Sonnet
The Petrarchan Sonnet was brought into England by Sir Thomas Wyatt, but the relative difficulty of finding rhyming words in English meant that the sonnet soon evolved into a more amenable form. The standard English sonnet, or Shakesperean sonnet, consists of three quatrains and a rhyming couplet. The rhyming scheme is abab cdcd efef gg. The most notable variant is the Spenserian sonnet which is rhymed abab bcbc cdcd ee.
The English poets were generally free with how they structured the mood of their piece, but the rhyming couplet at the end made for many a pithy conclusion. Famous Englishmen to utilise the sonnet include Samuel Daniel, Sir Phillip Sidney, Edmund Spenser and of course William Shakespeare.
The two following examples are both from sixteenth century England. The first is slightly unusual being a quatrain followed by a couplet repeated three times. It was written by Thomas Watson and appeared in his collection of poetry Hekatompathia in 1581. The second is by Shakespeare himself and is in the standard Shakesperean form. These poems have been chosen for their content as well as to give an example of structure, so it is worth noting that Watson's sonnet is a collection of high praise from various sources. The convention of extravagant praise had been established by Petrarch.
Thomas Watson, sonnet VII
Harke you that list to heare what sainte I serve: Her yellow locks exceede the beaten goulde; Her sparkeling eyes in heav'n a place deserve; Her forehead high and faire of comely moulde; Her wordes are music all of silver sounde; Her wit so sharpe as like can scarce be found; Each eyebrow hanges like Iris in the skies; Her Eagle's nose is straight of stately frame; On either cheeke a Rose and Lily lies; Her breath is sweete perfume, or hollie flame; Her lips more red than any corall stone; Her necke more white than aged swans yt mone; Her brest transparent is, like cristall rocke; Her fingers long, fit for Apollo's lute; Her slipper such as Momus dare not mocke; Her virtues all so great as make me mute: What other partes she hath I neede not say, Whose face alone is cause of my decaye.
Shakespeare, sonnet CXXX
My mistress' eyes are nothing like the sun; Coral is far more red than her lips' red; If snow be white, why then her breasts are dun; If hairs be wires, black wires grow on her head.
I have seen roses damasked, red and white, But no such roses see I in her cheeks, And in some perfumes is there more delight Than in the breath that from my mistress reeks.
I love to hear her speak, yet well I know That music hath a far more pleasing sound. I grant I never saw a goddess go; My mistress when she walks treads on the ground.
And yet, by heaven, I think my love as rare As any she belied with false compare