Yeats is no stranger to poetic forms. While the subject matter of his poems can get pretty weird, he likes to play up the traditional forms. Call him crazy.
This poem isn't as strict as some of his other poems, but it does have a formal rhyme scheme (the pattern of the rhymes), and it's composed of three stanzas (a block of lines that look like paragraph breaks) of four lines each, called quatrains. Take a look:
Stanza 1: ABAB
Stanza 2: CDCD
Stanza 3: EFEF
For example, in the first stanza, the end words (words at the end of the line) rhyme accordingly: Innisfree (A) rhymes with the end word in the third line, honey-bee (A); and made (B) rhymes with the fourth line's end word, glade (B). The pattern repeats itself perfectly throughout the rest of the poem. Tidy work by Yeats.
But wait. There's even more to it. If you read the poem carefully, you'll see that each line has about six stresses in it:
I will rise and go now and go to Innisfree.
Except for the last line of each stanza, which usually has four:
And live alone in the bee-loud glade.
Those six-stress lines are a little something we like to call hexameter. Wouldn't you know, that's the Latin term for a six-stress meter. Fancy. And those four-stress lines? Those are written in tetrameter.
In both cases, the lines usually have a sing-songy daDUM daDUM beat to them, but there are a ton of variations and exceptions throughout this poem. Usually, we would call a meter like this iambic, which is the term we use for meters that follow a pattern of unstressed, followed by stressed syllables. But in this case, there are an awful lot of exceptions to the rule. So we'll just call this one vaguely iambic.
And what's up with all this tidy work, exactly? Well, we here at Shmoop like to think that Yeats is playing with the sing-songy, traditional forms as a way to create this dreamy, beautiful, imaginary world. The lilting rhythm lulls us into his daydream of Innisfree, until we're cruelly awakened by the heavy sound of "deep heart's core."