The Shakespearean or English sonnet is a fourteen-line lyric poem written in iambic pentameter [five feet of an unstressed syllable followed by a stressed syllable (u /) ] that has three four-line quatrains followed by a concluding rhyming two-line couplet. The rhyme scheme of the Shakespearean sonnet is usuallyabab cdcd efef gg. Each of the three quatrains usually explores a different variation of the main theme. Then, the couplet presents a summarizing statement.
- Sonnet 18 (XVIII), however, varies in both form and content from the typical Shakespearean sonnet. For, rather than following the pattern of the Shakespearean sonnet, this sonnet has a distinct break between the first eight lines and the last six, a division more closely associated with the Petrarchan sonnet. This break is signaled by the semicolon at the end of line eight, and the contrasting conjunction But, which commences the ninth line. (This turn of thought is called a volta.) In addition to this contrast, Sonnet 18 also varies in content from the seventeen sonnets previous to it: For the first time, the poet expresses his desire to make youth immortal in his final couplet, so the couplet is more than the customary summation.
- Sonnet 30 (XXX) follows the pattern of the Shakespearean sonnet more closely that does Sonnet 18; yet, there is not the usual variation of theme in the three quatrains. Instead, the bewailing of the loss of loved ones is simply given more significance and weight as the weeping of the first quatrain moves from woe and moaning in the second quatrain to, finally, "heavily from woe to woe.../Which I new pay as if not paid before." Then, the couplet is not a summation, but a contrasting idea as the poet finds a solution to his woe by turning to his new love in which "All losses are restor'd, and sorrows end."
- Sonnet 130 (CXXX) differs in its theme, more than in its form as it parodies the use of hyperbole that the love poets of Shakespeare's time employed. At the same time, however, Shakespeare ridicules himself since he, too, uses hyperbole. While it is traditional for poets to compare the features of their lovers with the elements of nature, Shakespeare uses this imagery to return love poetry to reality. For instance, while the verb reeks denotes an offensive smell, in Shakepearean English it merely means smell; nevertheless, with this parody in mind, there may be the suggestion by Shakespeare that the perfume and breath are a bit excessive. In the final rhyming two lines, as in Sonnet 30, the couplet contains the solution: There must not be false comparison.