“September 1, 1939” is written in free verse, though it still retains the formal visual format popular at the time. It’s told through 99 concise lines divided into nine equal stanzas of 11 lines each. This makes it look like it follows a more rigid pattern than it really does, and creates a visual effect of bridging the old and the new—much like the speaker’s experience of the colliding old and new worlds. Additionally, each stanza ends on a period and uses enjambment to create one complete, run-on sentence for a total of nine sentences across the entire poem. This creates the sense that the poem is a spiraling internal monologue, with each stanza break representing a breath between ideas.

There is no consistent rhyme scheme, but the poem uses occasional end rhymes and internal rhymes to enhance its overall rhythm; for instance, the end rhymes in, “Uncertain and afraid / […] / Of a low dishonest decade” (Lines 3-5) and the near rhymes in, “And darkened lands of the earth / […] / The unmentionable odour of death” (Lines 8-10), both in the first stanza.