Intro
So that's nice about all those structures that make the baggy monsters we think of as novels seem like they fit some sort of pattern. But how about poetry? Let's look at a sonnet by Gerard Manley Hopkins, an English poet who lived in the 19th century. He was a good poet, but not a very happy guy.
Hopkins wrote a series of sonnets, which are innovative in many ways—for example, you wouldn't mistake them for Willy Shakespeare's earlier, usually romantic, sometimes satirical, potentially homoerotic sonnets, which comment on the role of a poet in general. But even Hopkins' way-less-upbeat works can tell us a lot about the structure of sonnets as a form of poetry.
Quote
I wake and feel the fell of dark, not day.
What hours, O what black hours we have spent
This night! what sights you, heart, saw; ways you went!
And more must, in yet longer light's delay.
With witness I speak this. But where I say
Hours I mean years, mean life. And my lament
Is cries countless, cries like dead letters sent
To dearest him that lives alas! away.
I am gall, I am heartburn. God's most deep decree
Bitter would have me taste: my taste was me;
Bones built in me, flesh filled, blood brimmed the curse.
Selfyeast of spirit a dull dough sours. I see
The lost are like this, and their scourge to be
As I am mine, their sweating selves; but worse.
Analysis
You thought sonnets were all about romance and roses? Think again. Hopkins wasn't thinking about the butterflies and the bees when he wrote this sonnet. But even though it's not about love, it's still a sonnet. But we structuralists are bound to ask—what makes it a sonnet, if not what it's about? What characteristics does it share with other poems of this type?
Well, starting with the poem's structure seems like a safe bet. It's got fourteen lines, which is important because poets almost always write sonnets in fourteen lines. Kind of like how you expect soda to come in a six-pack and roses to be by the dozen.
Another thing that distinguishes this as a sonnet is how the ideas and themes are developed over the fourteen lines. Even though those themes aren't about the poet's beloved, the movement from specific to general follows the pattern of a lot of other sonnets. Here, the first quatrain (that's four lines) describes a terrible night when Hopkins was tossing and turning and pretty much too weepy to get forty winks. The second quatrain (lines 5-8) reveals that actually, this isn't just one off night for the poor guy: it's years of depression that Hopkins has endured. And what's worse, even God isn't responding to Hopkins. And that's tough news if you're an Anglican who converted to Roman Catholicism and became a Jesuit priest, which is what Hopkins did. Not the best cure for insomnia, it turns out.
The last six lines of the poem spiral even deeper into despair: "I am gall, I am heartburn." Geez, can someone call a shrink for this guy? Then you have the last couplet—the final two lines which, in sonnet speak, are called a "volta" and typically introduce a second idea that contrasts the first one. Hopkins realizes that "The lost are like this, and their scourge to be/ As I am mine, their sweating selves; but worse." Here, Hopkins sees that as bad as it is for him, what with his depression and his alienation from God and all, it's even worse for non-believers, who are completely "lost" to God and to the Church. According to Hopkins, they've got a lot more to deal with than heartburn.
Okay, so we may not subscribe to Hopkins' ideas about believers and non-believers and all that I-am-gall stuff. The point is, even though the subject matter of this sonnet is pretty unusual (depressive insomnia + Jesuit priesthood = poetry?), we can see that in terms of the way the poem is put together, it shares core elements with other poems of this type. If we look at Shakespeare's sonnets, or Francesco Petrarch's, or John Donne's, or Philip Sidney's, we'll see that there are variations in terms of subject matter, and also in terms of rhythm and rhyme and the break-down of quatrains and sestets and so on. But despite these differences there will always be a volta—some turn in the poem that juxtaposes the idea of the first twelve lines with the final two. So the volta can be taken as one of core "structural" elements of the sonnet form.