Chapman writes in long rhyming couplets with a loose iambic heptameter, a form that was already archaic by 1611 and reads nothing like ordinary speech. His diction reaches for grandeur: "that invisible cave / That no light comforts" for the underworld, or "rarely magnified" for Achilles' beauty in Book 21. Green writes in free verse with variable line lengths and a contemporary register that stays close to speech without tipping into slang. His opening, "Wrath, goddess, sing of Achilles Pēleus's son's / calamitous wrath," places the Greek word order first and uses plain nouns. Chapman's rhyme scheme sometimes forces the sense: "Meet / victory" in Book 9 bends the Greek to fit the couplet. Green's rhythm is controlled but not metered, and his diacritical spellings (Hādēs, Arēs) mark him as someone addressing readers who may want some contact with the Greek names. Green treats fidelity to the Greek syntax as a priority. His Book 6 leaves passage, "As the generation of leaves, so is that of mankind," keeps the simile's structure intact and moves in four clean lines. Chapman's version, "The wind in autumn strows / The earth with old leaves then the spring the woods with new endows," is longer, more decorative, and adds "autumn," which is not in the Greek. In the Athena speech in Book 5, Green gives her the direct phrase "a two-faced / liar," which is blunt and modern; Chapman softens the characterization into moralizing commentary about just war. Chapman writes for performance and rhetorical effect, and his Achilles in Book 21 has a theatrical sweep. Green's Achilles, "Can't you see what I'm like," sounds conversational and immediate in a different way.
Achilles' baneful wrath resound, O Goddess, that impos'd
Infinite sorrows on the Greeks, and many brave souls loos'd
From breasts heroic; sent them far to that invisible cave
That no light comforts; and their limbs to dogs and vultures gave:
To all which Jove's will gave effect; from whom first strife begun
Betwixt Atrides, king of men, and Thetis' godlike son.
Wrath, goddess, sing of Achilles Pēleus's son's
calamitous wrath, which hit the Achaians with countless ills—
many the valiant souls it saw off down to Hādēs,
souls of heroes, their selves1 left as carrion for dogs
and all birds of prey, and the plan of Zeus was fulfilled
from the first moment those two men parted in fury,
Atreus's son, king of men, and the godlike Achilles.