Six lines are all Shelley gives us, and nearly everything in them turns on one failure of attention. A voice shakes as two people part, the speaker doesn't understand what he is hearing, and he walks away. Only later, and the whole poem is set in that "later," does he realise the voice came from a heart that "was broken." The title names the woman as Fanny Godwin, half-sister of Mary, who would become Shelley's wife. She took her own life in 1816. Knowing this turns the poem into an elegy shadowed by guilt, although the text never mentions a death or says what the speaker could have done.
The form works quietly to make that guilt felt. The first four lines rhyme ABAB, and all four rhyme words are "double" rhymes with an extra unstressed syllable at the end: *parted/departed*, *broken/spoken*. Those soft endings make each line trail away, like a voice fading or a sentence nobody finishes. The rhymes also carry meaning. "Parted" sits inside "departed," so the second rhyme is almost an echo of the first: she parts, he departs, and the sound can't move past the moment. Meanwhile "broken" is tied by sound to "spoken." The damage he failed to see is joined to the words he failed to take in, and the rhyme links cause and effect even though he did not.
The diction is plain, and each word does careful work. "Quiver" is the only physical detail in the poem. It is a small, involuntary tremor, the kind of sign that is easy to miss in the moment and unbearable to remember afterwards. The poem attends to a voice, not a face, so the clue arrives as sound, and sound is the thing the speaker admits he let pass. The inverted phrasing of "Yet knew I not" slows the line and gives it the formality of a confession. Then comes the sharpest word of the quatrain, "Heeding." He doesn't say he failed to hear her. He says he did not heed her, which is worse, because hearing is accidental and heeding is a choice not made. The words "then spoken" are never reported. We are shut out exactly as he was, and that blank may be the most unsettling thing in the poem. Whatever she said, whatever might have been a plea, is lost.
In the last two lines the poem stops narrating and cries out. "Misery--O Misery" breaks into repetition, a dash and an exclamatory "O," as if the controlled, reflective voice of the first four lines has given way. Misery is addressed as "thee," as though it were a person, or a wanderer needing somewhere to rest. The closing line, "This world is all too wide for thee," is deliberately open. It could mean that the world is so vast that suffering has nowhere to hide or be sheltered. Or it could mean that a grieving person can be lost in such a wide world that no one near enough hears her. That second reading connects with the scene of parting, where distance and inattention did the damage. The idiom "all too," as in "all too late," also quietly adds regret. After the falling double rhymes, the poem ends on a single stressed syllable, "thee," an open vowel that sounds like a sigh and leaves no echo behind it.
Shelley is often remembered for sweeping, visionary writing, as in "Ode to the West Wind." Here he does the opposite and holds back. There is no grand argument about grief, just a short, strict scene and an unanswerable question inside it. The poem is worth studying because it shows how little a poem needs to say to hurt. It captures a very ordinary human experience, the last conversation we didn't listen to properly, and shows how hindsight turns a tremor in a voice into a verdict on ourselves. The speaker cannot go back, and the poem's six lines are as far as he gets.