In addition to dividing a Shakespearean sonnet into quatrains and a couplet, analysts talk about its “octave” and “sestet.” The octave is the first eight lines, or two quatrains, and it introduces the poem’s topic and offers a certain view of it. The sestet is the final six lines, or the third quatrain plus the couplet. Many Shakespearean sonnets have a shift in perspective, or “volta,” as the sestet begins. For instance, Shakespeare’s Sonnet 18 begins, “Shall I compare thee to a summer’s day?” and the octave describes the problems with a summer’s day: The sun can be too hot, it’s windy, the lovely flowers eventually die. The sestet begins with a shift: “But thy eternal summer shall not fade.” The remainder of the poem suggests that the youth it addresses is superior to a summer’s day because its beauty is everlasting, immortalized in the text.