Butler writes in plain prose, with no line breaks and no attempt to reproduce the rhythmic shape of Greek hexameter. His diction is mostly neutral Victorian English: "many a brave soul," "man after my own heart," "villain incarnate." Merrill writes in English hexameters, a long line with a fixed stress pattern that creates an audible pulse across every passage. His diction runs toward the formal and slightly archaic: "scion of Peleus," "single-hoofed horses," "treacherous turncoat." In the Book 9 passage, Butler gives Achilles's choice in one tight sentence, while Merrill takes seven lines, repeating "lost is" twice to mirror the Greek's parallel structure. That repetition is a direct rhythmic feature of the original; Butler cuts it for speed. Each translator sets a different priority. Butler removes nearly everything that slows a reader down. He changes Achilles's two formal fate-clauses in Book 9 into a quick either/or, and in Book 21 he skips several lines of the Greek entirely, dropping the detail about dawn, midday, and evening as possible times of Achilles's death. The result reads fast and stays clear, but the speech loses its weight. Merrill stays closer to the Greek line count and preserves the repeated phrasing. In the leaves passage from Book 6, Merrill keeps the full comparison through four lines; Butler collapses it and adds a phrase, "the new spring up as the old are passing away," that has no equivalent in the Greek. Merrill's approach requires more attention from the reader; Butler's requires less.
Sing, O goddess, the anger of Achilles son of Peleus, that brought countless ills upon the Achaeans. Many a brave soul did it send hurrying down to Hades, and many a hero did it yield a prey to dogs and vultures, for so were the counsels of Jove fulfilled from the day on which the son of Atreus, king of men, and great Achilles, first fell out with one another.
Sing now, goddess, the wrath of Achilles the scion of Peleus,
ruinous rage which brought the Achaians uncounted afflictions;
many the powerful souls it sent to the dwelling of Hades,
those of the heroes, and spoil for the dogs it made of their bodies,
plunder for all of the birds, and the purpose of Zeus was accomplished—
sing from the time when first stood hostile, starting the conflict,
Atreus' scion, the lord of the people, and noble Achilles.