How did Plato distinguish affirmation from negation in the Sophist?

In his work Sophist, Plato distinguished affirmation from negation as part of his broader analysis of the internal structure of language and statements (logos).1

He established that a complete statement requires at least one name (including nouns and adjectives) and one verb, a foundational distinction that allowed for the investigation of how statements are constructed. Furthermore, Plato addressed the philosophical problem of Not-Being by reinterpreting it as heteron, or "difference". He argued that the true antinomy is not between Being and Not-Being, but between tauton (the object of consciousness in its present determination) and heteron (all other things from which that object is distinguished). By characterizing Not-Being as a being defined by its difference from another, Plato provided a logical framework for understanding negation as a relational distinction rather than a simple contradiction of existence.12