The topic is ancient Greek terms for knowing: three main verbs, three cognate nouns, how to translate them, and how to understand the relation between translation issues and philosophical interpretation. Central are the schemas devised by John Lyons, in Structural Semantics: An Analysis of Part of the Vocabulary of Plato (Oxford, 1961). So far as Plato is concerned I favour Lyons’ original book account, as against his subsequent accommodation to the Rylean distinctions which so dominated scholarly discussion in Barnes’ and my youth. Besides the extensive texts of Plato and Aristotle, there is an account of Simplicius disagreeing with Alexander about the four knowledge verbs in the first sentence of Aristotle’s Physics. I close by elucidating Heraclitus frag. 57.