“Prufrock” has an irregular rhyme scheme, which is typical for a poem written in free verse. But though it may be irregular, the rhyme scheme isn’t random. Indeed, Eliot constantly moves between rhymed and unrhymed lines, initiating a tension that’s emblematic of a larger thematic conflict between tradition and modernity. For example, much of the poem features rhyming couplets. Though the variable line lengths make the timing of the rhymes a bit unstable, the couplet nonetheless reads as a highly traditional form. Yet quite often Eliot interrupts these couplets with an unrhymed line that throws off the balance in a surprising way. He uses this tactic to significant effect in the poem’s opening three lines:

     Let us go then, you and I,
     When the evening is spread out against the sky
     Like a patient etherised upon a table

“Prufrock” famously begins with a couplet that sets up an expectation for a romantic description of sunset. However, Eliot follows this traditional-sounding couplet with an unrhymed line which deflates that expectation with a decidedly modern simile: “Like a patient etherised upon a table.” The twist is as shocking as it is humorous, and it foreshadows the way the poem will continue to move between registers of earnestness and irony.

In addition to signaling a tension between the speaker’s allegiance to tradition and his experience of modernity, the rhyme in the poem also illustrates the movements of the speaker’s thoughts. Much like Shakespeare’s Hamlet, whom he references in line 111, Prufrock is obsessive and indecisive, and he often lets himself get a bit carried away. Sometimes, Eliot illustrates suggests this obsessiveness with internal rhymes, as in lines 31–34:

     Time for you and time for me,
     And time yet for a hundred indecisions,
     And for a hundred visions and revisions,
     Before the taking of toast and tea.

Other times, Eliot stretches rhymes far beyond the basic couplet form to show how the speaker gets hooked into unproductive thinking. One such moment occurs in lines 37–44:

     And indeed there will be time
     To wonder, “Do I dare?” and, “Do I dare?”
     Time to turn back and descend the stair,
     With a bald spot in the middle of my hair
     (They will say: “How his hair is growing
thin!”)
     My morning coat, my collar mounting firmly to the
chin,
     My necktie rich and modest, but asserted by a simple
pin
     (They will say: “But how his arms and legs are
thin!”)

In this passage, Prufrock upsets himself by imagining insults that people might criticize his balding head or his slender physique. Even as he attempts to walk and dress elegantly, he can’t help but tear himself down with obsessively self-critical thoughts that Eliot emphasizes with a trio and then a quartet of insistent rhymes. In these instances, as well as others, rhyme has a strongly ironic presence in the poem. Such an ironic presence once again asserts a tension between traditional poetic forms, in which rhyme is unproblematic, and modern poetic forms, which either turn rhyme on its head or else abandon it altogether.