Red Alert! We're about to use a lot of numbers. But this is part of what makes Dylan Thomas such a rock star. It's like he's riffing perfectly matched bars of music over and over again with his pen. Confused? Don't worry, when you read the poem, your ear picked up on the form whether you noticed it or not. We're just going to break it down for you, Shmoop-style.
Technically, "Fern Hill" is not written in a traditional form. But it's not exactly free verse, either. Each stanza has 9 lines and sticks to a strict syllabic count:
These numbers would be arbitrary, except that Thomas sticks to them for each stanza of the poem. So each stanza has the exact same number of lines with the exact same number of syllables in each line. We call that open verse, which is meant to suggest that this poem has a form all its own. Sure, it's no sonnet, but free verse it ain't either.
The point is that Dylan Thomas has created his own restraints, and these restraints act as an anchor for the rhythm and voice of the poem to express the speaker's strong emotions without becoming too chaotic. It's like a frame in which Thomas paints his picture of Fern Hill.
But syllable counts aren't the only tool in Thomas's box. He also uses sound play like a boss. Read the poem aloud to yourself, and you'll hear long E's in words like easy, lilting, happy, green, starry, me, carefree, be, mercy and means, and that's just the first two stanzas. If you keep on reading, more assonance keeps popping up everywhere you look.
And he doesn't stop there. Internal rhymes, like "among wagons" and alliteration abound. Actually, alliteration more than abounds. It practically takes over the poem. There are so many examples we don't even know where to start. But suffice it to say, if you read this poem aloud with an ear for repeated sounds, you'll find yourself making music in no time.
Why all this repetition? It accomplishes a few things for the poem. First, it makes this sucker sound an awful lot like a song. We mean, it practically sings itself. But more than that, it adds structure to a dreamlike world of childhood memories. This, combined with Thomas's rampant enjambment, means that the poem is constantly circling back on itself, creating a web, or an echo chamber of meaning. We can't read each stanza that comes without thinking of it in terms of the sounds and images of the last. As we read, we, too, are constantly circling back, which conveniently mimics the speaker's obsession with his own past. And much like his childhood, it all ends far too soon.