What are the differences between Shakespeare sonnet and petrarchan sonnet?

Shakespearean sonnet and Petrarchan sonnet are two of the most prominent sonnet forms in Western literature. Both are crafted of fourteen lines, though there are key dissimilarities between the two forms.

Shakespearean sonnet:

- Rhyme Scheme: ABAB CDCD EFEF GG

- Structure: Composed of four quatrains (four-line stanzas) and a final couplet (two-line stanza)

- Focus: Typically presents a problem, question, or dilemma in the quatrains and offers a resolution, epiphany, or twist in the couplet.

Petrarchan sonnet:

- Rhyme Scheme: ABBA ABBA CDCDCD or CDECDE

- Structure: Comprises an eight-line octave (two quatrains) followed by a six-line sestet (three-line stanzas or one six-line stanza)

- Focus: Presents an initial situation or argument in the octave and an introspective or reflective turn in the sestet.

Additionally, Shakespearean sonnets employ iambic pentameter (a rhythmic pattern of unstressed-stressed syllables) throughout the entire sonnet, while Petrarchan sonnets may feature variations in the meter, such as the use of iambic tetrameter (eight syllables per line) in the sestet.