Shakespeare begins “Sonnet 18” with the famous question, “Shall I compare thee to a summer's day?” In doing so, he invites readers to picture a scene and to consider the nature of the inquiry for themselves.
First, with this question, Shakespeare invites us into his conversation with his beloved. We can picture the two of them sitting side by side. The poet is trying to think of a way to best praise his beloved. What will work? He might consider flowers or candy or perhaps even gentle birds, but none of these will do. Perhaps he is even discussing each of these possibilities with her and rejecting them one by one. As he looks into his beloved's eyes, he tries one more and asks her about it: “Shall I compare thee to a summer's day?”
This comparison seems to have possibilities, so the poet follows through with it. As he continues the thought, however, again discussing it with his beloved, he discovers that a summer's day is not quite so apt as he first assumed. Indeed, his beloved is “more lovely and more temperate” (line 2). Summer days are sometimes accompanied by “rough winds” (line 3) or weather that is too hot, and summer fades quickly. No, he decides that a summer's day will simply not do to praise his love. She is much more beautiful than a typical summer's day.
Second, the question invites readers to consider the nature of the inquiry for themselves. Questions open up opportunities for reflection and draw readers into a text. We might picture the best summer's day we've ever experienced—or, on the other hand, perhaps we remember the worst. We might meditate on a person whose personality suggests the brightness of a summer's day or on someone else whose character is more like a summer thunderstorm. Our thoughts might turn to ourselves and ponder how we, too, may in some way reflect a summer's day. Finally, we might, as the poet does, contemplate the fleeting nature of a summer's day and compare that to the fleeting nature of life itself.