This folks, is a standard sonnet: fourteen lines in iambic pentameter. More specifically, it fits the mold of a Shakespearean sonnet. Not sure what that means? Let Uncle Shmoop explain:
Don't let the fancy names intimidate you – iambic pentameter is simple once you get the hang of it.
An "iamb" is an unaccented syllable followed by an accented one. One iamb makes the sound da-DUM.
"Penta" means five, and "meter" refers to a regular rhythmic pattern. So "iambic pentameter" is a kind of rhythmic pattern that consist of five iambs per line. It's the most common rhythm in English poetry and sounds like five heartbeats:
da-DUM da-DUM da-DUM da-DUM da-DUM
Let's try it out on the first two lines from "When I have fears that I may cease to be." We've put the stressed syllables in bold italics and divided up the iambs with slashes.
When I | have fears | that I | may cease | to be
Be-fore | my pen | has glean'd | my teem|-ing brain,
Every second syllable is accented (stressed), so this is classic iambic pentameter. (Note: the word "gleaned" is pronounced with only one syllable and sounds like "glean'd.") Overall, the meter of the poem is in a fairly strict iambic pentameter.
Shakespearean sonnets all share a specific format:
But wait: let's break that down just a little bit: why would Keats choose to use Shakespeare's sonnet form to begin with? Well, Shakespearean sonnets tend to be about deep emotions, like love or the desire for immortality. (If you want to see some great examples of Shakespeare's own wild desires, see our guides to his sonnets.) In that way, channeling your emotions through a form that historically tends towards the melodramatic seems like a pretty natural choice, right?
The "turn" is a really cool feature of a sonnet, so we thought we'd add a bit more detail here. In a sonnet, the first section of the poem develops a single concept (or, as in the case of "When I fear that I may cease to be," several cumulative thoughts). Then the poem "turns." The second section reverses these thoughts, taking the poem into entirely new and surprising directions. In this case, Keats spends the first twelve (okay, eleven and a half) lines exploring the agonizing combinations of his desires (for love and success) and his certainty that death will cut those desires short. The last two and a half lines reject all of Keats' desires as futile. All of that passion? Worthless. All that desire? Not worth thinking about.
Keats' turn in this poem is pretty standard, but he does sort of rush into his emotional reversal. Instead of starting his change of pace at the beginning of a new line, he actually starts it halfway through line 12. Check out what we mean:
And when I feel, fair creature of an hour!
That I shall never look upon thee more,
Never have relish in the faery power
Of unreflecting love;—then on the shore
Of the wide world I stand alone, and think,
Till Love and Fame to nothingness do sink.
We've included last quatrain (group of four lines) in addition to the final couplet (group of two rhyming lines) just so you can get a sense of how sudden this transition is. Why do you think Keats made his turn so non-standard? Is he eager to get to the turn? Hesitant? Maybe, that doesn't seem like such a huge deal, but, when you're dealing with a form as established and well-used as the Shakespearean sonnet, any derivation is worth noting.