Roethke wrote “My Papa’s Waltz” in iambic trimeter, which means that every line in the poem consists of three iambic feet. (Recall that an iamb is a metrical foot made up of one unstressed and one stressed syllable, as in the word “un-til.”) Iambic trimeter is a slightly unusual meter for poetry. Certain poetic forms—such as ballads—do sometimes feature iambic trimeter alongside longer lines of verse, but poets don’t often compose whole poems in trimeter. Even so, trimeter turns out to be the perfect meter for Roethke’s poem, since the three-beat meter mimics the three-beat rhythm characteristic of the waltz. The use of such short lines also echoes the pace of many waltzes, which often race at a fast clip and force the dancers to spin each other around in dizzying circles. Roethke evokes this dizzying pace throughout the poem, but especially in the opening four lines:

     The whis- | key on | your breath   
     Could make | a small | boy diz- | zy;   
     But I | hung on | like death:   
     Such waltz- | ing was | not ea- | sy.

Whereas the first and third lines are strict examples of iambic trimeter, the second and fourth lines each finish with an extra unstressed syllable. This extra syllable throws the waltz rhythm off ever so slightly, indicating a sense of instability as the speaker attempts to keep pace with his father.