At the beginning of the poem, the speaker poses a rhetorical question when he asks: "What happens to a dream deferred?" Throughout the rest of the poem, the speaker implies answers to that initial rhetorical question through a series of other rhetorical questions. For example, the speaker asks, "Does it dry up / like a raisin in the sun?" By asking this rhetorical question, the speaker means to imply that dreams do indeed "dry up" if they are deferred. The speaker then asks if a dream deferred will "fester like a sore," and the implied answer is that it will. By posing a series of rhetorical questions the speaker encourages the readers to think for themselves about what happens to dreams that are deferred, or put off. The speaker perhaps hopes that in thinking for themselves the readers might also think of personal dreams that they have deferred, and regretted deferring.
The speaker also uses similes to impress upon the reader the danger of deferring one's dreams. He uses similes to suggest that a dream deferred is "like a sore" and "like rotten meat." These are vivid and striking images which help the reader to visualize and thus better appreciate what happens to dreams that are deferred. A "sore" connotes pain, and "rotten meat" suggests illness and disease. The speaker thus means to convey that a dream that might start as beautiful and invigorating will become ugly, painful and diseased if left to, as it were, rot unfulfilled. The speaker also uses a simile when he says that a dream deferred is "like a heavy load," implying that one can be weighed down metaphorically by the weight of a dream which one did not try to fulfil.