“North” consists of ten unrhymed quatrains—stanzas of four lines—without a consistent meter. The poem shares some elements with the ode, which is a type of lyric poetry directed toward the appreciation or celebration of a particular person, place, or object. Odes have no specific formal requirements and are defined by their subject matter and tone. However, while “North” echoes odes like Keats’s “Ode on a Grecian Urn,” it has a much more passive and fleeting relationship with its subject matter. For instance, the poem begins with the speaker’s view of “the Atlantic thundering” before the raiders “suddenly” appear (Lines 4, 8), occasioning a mediation on historical artifacts—a mutability of subject that is uncharacteristic of traditional odes.

Heaney’s poem, then, is best understood as free verse, or poetry without any traditional formal restrictions. Instead, “North” relies on Heaney’s careful use of vowel and consonant sounds to give the poem a spoken rhythm that plays with the sounds of Old English alliterative verse. Heaney’s partial engagement with this antiquated form, structured around the quality of a word’s sound rather than its stresses, reinforces the poem’s messages about the value of oral poetry traditions.