நன்னூல்
Naṉṉūl — The Good Book
Pavananti Muṉivar · c. 12th–13th century CE · Classical Tamil Grammar
Four hundred and sixty-two grammatical sūtras — the complete account of the Tamil language by Pavananti Muṉivar, one of the great grammarians of the Tamil tradition. Where every other work in this library is a poem or a hymn, the Naṉṉūl is the grammar that made them possible: the rules of the letters, the words, the sounds. The invisible architecture beneath all of Tamil literature, made visible.
Two pillars of the Tamil language
The study of the Tamil sound-system and writing system: the twelve vowels, eighteen consonants, their classification and order, the phonological rules governing word structure, and the sandhi (puṇarcci) rules of sound combination at word boundaries.
The comprehensive grammar of Tamil words: nouns and their seven cases, verbs and their three tenses, particles, qualifying words, non-finite verbal forms, and the rules of word formation — the complete morphology and syntax of classical Tamil.