Sonnet 30 up of fourteen lines in three quatrains and a couplet, rhyming "abab cdcd efef gg". While using the rhyming and metrical structure of the 'English' or 'Surreyan' sonnet, Shakespeare often also reflected the rhetorical form of the Italian form also known as the Petrarchan sonnet. It divides the sonnet into two parts: the "octet" (the first eight lines) usually states and develops the subject, while the "sestet" (the last six lines) winds up to a climax. Thus a change in emphasis, known as the "volta", occurs between the end of the eighth and the beginning of the ninth lines —
Sonnet 118 beginning with the third quatrain. Traditionally the administering of emetics, the trope worked in Sonnet 118, had three purposes: to renew the palate, to forestall the onset of sickness, and to counteract poison. The sonnet also picks up the motif of "palate", "cup", and "poison", left off at the end of Sonnet 114. The first pair of lines describes how "we our pallat urge"; "urge" means to 'intensify' or 'sharpen' the taste, but the word was used also of distillations which are 'urged' to a degree that a compound is yielded. "Appetites" are sharpened or made more acute ("more keen")