Part of speech

Lore & Background

The classification of words into lexical categories is found from the earliest moments in the history of linguistics. In the Nirukta, written in the 6th or 5th century BCE, the Sanskrit grammarian Yāska defined four main categories: nāma (noun, including adjective), ākhyāta (verb), upasarga (pre-verb or prefix), and nipāta (particle, invariant word). These were grouped into inflectable (nouns and verbs) and uninflectable (pre-verbs and particles). The ancient Tamil grammar Tolkāppiyam, argued to have been written around the 2nd century CE, classifies Tamil words as peyar (noun), vinai (verb), idai (part of speech modifying relationships between verbs and nouns), and uri (word further qualifying a noun or verb).

Reader's Guide

In the Western tradition, a century or two after Yāska, the Greek scholar Plato wrote in his Cratylus dialogue that sentences are a combination of verbs and nouns. Aristotle added a class called 'conjunction,' which included not only conjunctions but also other parts (interpretations differ; in one interpretation it includes pronouns, prepositions, and the article). By the end of the 2nd century BCE, grammarians had expanded this into eight categories, seen in the Art of Grammar attributed to Dionysius Thrax: noun, verb, participle, article, pronoun, preposition, adverb, and conjunction. The Latin grammarian Priscian modified this system, excluding article (since Latin lacks articles) but adding interjection. Modern English grammar generally follows this European tradition, though participles are now regarded as verb forms, and numerals are often conflated with other parts of speech. Eight or nine parts of speech are commonly listed: noun, verb, adjective, adverb, pronoun, preposition, conjunction, interjection, and determiner. Some modern classifications include additional classes such as particles and postpositions. The classification is still followed in most dictionaries.

Did You Know?

• The Sanskrit grammarian Yāska defined four main categories of words in the Nirukta, written in the 6th or 5th century BCE.
• The ancient Tamil work Tolkāppiyam, argued to have been written around the 2nd century CE, classifies Tamil words into peyar, vinai, idai, and uri.
• The Greek scholar Plato wrote in his Cratylus dialogue that sentences are a combination of verbs and nouns.
• The Latin grammarian Priscian modified the eightfold Greek system by excluding 'article' and adding 'interjection.'