"Few foreign masterpieces can have suffered more than Eugene Onegin from the English translator's failure to convey anything more than—at best—the literal meaning. It is as if a sound-proof wall separated Pushkin's poetic novel from the English-reading world. ...
Vladimir Nabokov's rendering into unrhymed iambics reproduces the exact meaning, but explicitly disclaims any further ambition. While Nabokov admits that in losing its rhyme the work loses its 'bloom' he argues, irrefutably, that no rhyming version can be literally accurate. It can however certainly strive for something else. It can attempt to produce some substitute for the 'bloom' of the original, without which the work is completely dead. It can try to convey the poet's tone of voice, whether world-weary or romantic, the sparkle of his jokes, the flavour of his epigrams, the snap of his final couplets. None of these effects can emerge from a purely literal unrhymed translation. In fact, to offset the inevitable loss in verbal exactness, a rhyming version can aim at a different sort of accuracy, an equivalence or parallelism conveying, however faintly, the impact of the original."
— Charles H. Johnston, "Translator's Forward to Eugene Onegin"