Part of speech
A category of words with similar grammatical properties.
A part of speech (abbreviated as POS or PoS), also known as a word class or grammatical category, is a category of words that share similar grammatical properties. Words assigned to the same part of speech generally display similar syntactic behavior, sometimes similar morphological behavior, and even similar semantic behavior. Commonly listed English parts of speech include noun, verb, adjective, adverb, pronoun, preposition, conjunction, interjection, numeral, article, and determiner. In modern linguistic classifications, terms such as word class, lexical class, and lexical category are often used, though some authors restrict "lexical category" to content words, excluding function words like pronouns. The term "form class" is also employed but has conflicting definitions. Word classes are divided into open classes, which readily acquire new members (such as nouns, verbs, and adjectives), and closed classes, which rarely do (such as pronouns and conjunctions). Almost all languages possess the classes of noun and verb, but beyond these, significant variation exists. For instance, Japanese has three classes of adjectives where English has one; Chinese, Korean, Japanese, and Vietnamese feature nominal classifiers; and many languages do not distinguish between adjectives and adverbs or between adjectives and verbs. Consequently, analysis of parts of speech must be performed for each individual language, though labels are assigned based on universal criteria. The classification of words into lexical categories dates to early linguistics. In the 6th or 5th century BCE, the Sanskrit grammarian Yāska defined four categories in the Nirukta: noun (including adjective), verb, pre-verb or prefix, and particle. The ancient Tamil work Tolkāppiyam classified words as noun, verb, a relational part of speech, and a qualifier. In the Western tradition, Plato distinguished verbs and nouns, and Aristotle added a conjunction class. By the 2nd century BCE, Dionysius Thrax’s Art of Grammar expanded this to eight categories: noun, verb, participle, article, pronoun, preposition, adverb, and conjunction. The Latin grammarian Priscian modified this system by excluding article and adding interjection. English grammar follows this European tradition, though participles are now treated as verb forms, and numerals are often merged with nouns, adjectives, or other classes.
- field
- Linguistics, Grammar
- known_for
- Categorizing words by grammatical properties; foundational to syntactic and morphological analysis
- variation
- Almost all languages have noun and verb classes, but significant variations exist across languages
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.'
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