The sonnet (from the Italian sonetto, meaning "little song") is a fourteen-line lyric poem, invented in the Renaissance, and perfected by the 14th century humanist Francesco Petrarch. A remarkably resilient form, for the past 600 years the sonnet has been harnessed by the creative genius of poets from Edumund Spenser to W.H. Auden. Critics have identified a wide variety of classifications, but suffice to say the two characteristic sonnet types are the Italian or Petrarchan, and the English or Shakespearean. The latter is marked by a traditional division into two parts: the first is the octave, a division of eight lines with a rhyme scheme of abbaabba; the second is the sestet, a division of six lines with a rhyme scheme of cdecde, cdccdc or cdedce. The transition from the first to the second is called (in Italian), the volta. This structure imparts a dialectical nature to the sonnet. Thus, the octave establishes the argument - or narrative, or query, or problem -, while the sestet resolves the situation through an abstract comment, a saving proposition, or a solution. So much for the traditional Italian sonnet. English poets, from Shakespeare onward have dispensed with the bipartite division, have varied the rhyme scheme, but within limits. And although iambic pentameter is the essential meter for the Italian sonnet, English poets have experimented with other meters. In fact, the sonnet in English is so different from the Italian that it permits a separate classification. Typically, the Shakesperean sonnet is composed of three quatrains, and a rhyming couplet to conclude. Thus, the dialectical structure is replaced by an epigrammatic one: the rhyming couplet acts as a kind of comment or interpretation of the three quatrains going before.