YāskaYāska was an ancient Indian grammarian and linguist [est. 7th–5th century BCE(disputed)]. Preceding Pāṇini [est. 7th–4th century BCE(disputed)], he is traditionally identified as the author of Nirukta, the discipline of "etymology" (explanation of words) within Sanskrit grammatical tradition and the Nighantu, the oldest proto-thesaurus in India. Yaska is widely regarded as the precursive founder of the discipline of what would become etymology in both the East and the West.
Epistemic modalityEpistemic modality is a sub-type of linguistic modality that encompasses knowledge, belief, or credence in a proposition. Epistemic modality is exemplified by the English modals may, might, must. However, it occurs cross-linguistically, encoded in a wide variety of lexical items and grammatical structures. Epistemic modality has been studied from many perspectives within linguistics and philosophy. It is one of the most studied phenomena in formal semantics. (a) grammatically: through modal verbs (e.g.
Yes and noYes and no, or similar word pairs, are expressions of the affirmative and the negative, respectively, in several languages, including English. Some languages make a distinction between answers to affirmative versus negative questions and may have three-form or four-form systems. English originally used a four-form system up to and including Early Middle English and Modern English has reduced to a two-form system consisting of yes and no. It exists in many facets of communication, such as: eye blink communication, head movements, Morse Code, and sign language.