Butler writes in prose, and his sentences move at a steady, explanatory pace. His diction leans archaic: "many a brave soul," "man after my own heart," "villain incarnate." Johnston writes in verse, with line breaks that create small pauses and a register that sits closer to ordinary speech. In the Book 21 passage, Butler gives "I am great and goodly," while Johnston writes "You see how fine I am, / how tall, how handsome?" The first sounds formal and distanced; the second puts the boast in Achilles' mouth with something closer to conversational directness. Johnston's line breaks do rhythmic work that Butler's prose cannot, but Butler's longer sentences sometimes carry more of the Greek's forward momentum in a single uninterrupted movement. Butler's prose prioritizes readability over reproduction of the Greek's formal qualities. He sometimes compresses. In the Book 9 passage he gives only "my name will live for ever," cutting the detail about Thetis and the two fates that Johnston keeps in full. Johnston stays closer to the Greek's architecture, naming "silver-footed Thetis" and the two fates explicitly, which matches what the Greek actually says. His verse format also makes the text easier to read aloud, which matters for a poem built for performance. Butler's prose is more compact and moves faster on the page, which some readers find easier to absorb. Johnston's version asks more of the reader's attention but returns more of the original's structure.
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, Goddess, sing the rage of Achilles, son of Peleus—
that murderous anger which condemned Achaeans
to countless agonies and threw many warrior souls
deep into Hades, leaving their dead bodies
carrion food for dogs and birds—
all in fulfilment of the will of Zeus.