In “To an Athlete Dying Young,” how are the couplets arranged?

The couplets are arranged in four-line stanzas (thus 2 x 2 couplets = four lines). A four-line stanza is called a quatrain. The couplets have the exact rhymes at the end of the lines. The lines are composed of iambic tetrameter; there are four accents in each line and iambic gives the rhythm (the accent is on every other syllable basically).

The couplets are arranged in four-line stanzas.