Cara in San Diego, California, notes that the word monologue refers to something spoken by one person while dialogue involves two people speaking, and that a bicycle has two wheels and a unicycle has one. So why aren’t they monocycles and dicycles? ONe part of the answer: the di- in dialogue is from the Greek word dia- meaning through, not two. For a thorough exploration of these and other affixes in English, check out Michael Quinion’s affixes.org. This is part of a complete episode.