Well, &quot;yes&quot; and &quot;no&quot; are (or should be) only a part of a more (logically) complete answer that is usually implied and therefore not mentioned. Derived from your example:<p>&quot;(Are you) hungry?&quot; - &quot;Yes(, I am hungry)!&quot;&#x2F;&quot;No(, I am not hungry)!&quot;<p>I assume that the adverbs &quot;yes&quot; and &quot;no&quot; initially occurred as optional parts of an answer (only to later cast their supplementary part of the answer as the optional one). Curious enough, now when I&#x27;m thinking about it, I remember utterances with the usage of &quot;yes&quot; in the questions themselves (especially on some immigrants) - like &quot;Hungry, yes?&quot; I wonder what will this evolve into down the road...