In grammar, a part of speech or part-of-speech (abbreviated as POS or PoS, also known as word class or grammatical category) is a category of words (or, more generally, of lexical items) that have similar grammatical properties. Words that are assigned to the same part of speech generally display similar syntactic behavior (they play similar roles within the grammatical structure of sentences), sometimes similar morphological behavior in that they undergo inflection for similar properties and even similar semantic behavior. Commonly listed English parts of speech are noun, verb, adjective, adverb, pronoun, preposition, conjunction, interjection, numeral, article, and determiner. Other terms than part of speech—particularly in modern linguistic classifications, which often make more precise distinctions than the traditional scheme does—include word class, lexical class, and lexical category. Some authors restrict the term lexical category to refer only to a particular type of syntactic category; for them the term excludes those parts of speech that are considered to be function words, such as pronouns. The term form class is also used, although this has various conflicting definitions. Word classes may be classified as open or closed: open classes (typically including nouns, verbs and adjectives) acquire new members constantly, while closed classes (such as pronouns and conjunctions) acquire new members infrequently, if at all. Almost all languages have the word classes noun and verb, but beyond these two there are significant variations among different languages. For example:
Japanese has as many as three classes of adjectives, where English has one. Chinese, Korean, Japanese and Vietnamese have a class of nominal classifiers. Many languages do not distinguish between adjectives and adverbs, or between adjectives and verbs (see stative verb). Because of such variation in the number of categories and their identifying properties, analysis of parts of speech must be done for each individual language. Nevertheless, the labels for each category are assigned on the basis of universal criteria.
History The classification of words into lexical categories is found from the earliest moments in the history of linguistics.
India In the Nirukta, written in the 6th or 5th century BCE, the Sanskrit grammarian Yāska defined four main categories of words:
नाम nāma – noun (including adjective) आख्यात ākhyāta – verb उपसर्ग upasarga – pre-verb or prefix निपात nipāta – particle, invariant word (perhaps preposition) These four were grouped into two larger classes: inflectable (nouns and verbs) and uninflectable (pre-verbs and particles). The ancient work on the grammar of the Tamil language, Tolkāppiyam, argued to have been written around 2nd century CE, classifies Tamil words as peyar (பெயர்; noun), vinai (வினை; verb), idai (part of speech which modifies the relationships between verbs and nouns), and uri (word that further qualifies a noun or verb).
Western tradition A century or two after the work of Yāska, the Greek scholar Plato wrote in his Cratylus dialogue, "sentences are, I conceive, a combination of verbs [rhêma] and nouns [ónoma]". Aristotle added another class, "conjunction" [sýndesmos], which included not only the words known today as conjunctions, but also other parts (the interpretations differ; in one interpretation it is pronouns, prepositions, and the article). By the end of the 2nd century BCE, grammarians had expanded this classification scheme into eight categories, seen in the Art of Grammar, attributed to Dionysius Thrax:
'Name' (ónoma) translated as 'noun': a part of speech inflected for case, signifying a concrete or abstract entity. It includes various species like nouns, adjectives, proper nouns, appellatives, collectives, ordinals, numerals and more. Verb (rhêma): a part of speech without case inflection, but inflected for tense, person and number, signifying an activity or process performed or undergone Participle (metokhḗ): a part of speech sharing features of the verb and the noun Article (árthron): a declinable part of speech, taken to include the definite article, but also the basic relative pronoun Pronoun (antōnymíā): a part of speech substitutable for a noun and marked for a person Preposition (próthesis): a part of speech placed before other words in composition and in syntax Adverb (epírrhēma): a part of speech without inflection, in modification of or in addition to a verb, adjective, clause, sentence, or other adverb Conjunction (sýndesmos): a part of speech binding together the discourse and filling gaps in its interpretation It can be seen that these parts of speech are defined by morphological, syntactic and semantic criteria. The Latin grammarian Priscian (fl. 500 CE) modified the above eightfold system, excluding "article" (since the Latin language, unlike Greek, does not have articles) but adding "interjection". The Latin names for the parts of speech, from which the corresponding modern English terms derive, were nomen, verbum, participium, pronomen, praepositio, adverbium, conjunctio and interjectio. The category nomen included substantives (nomen substantivum, corresponding to what are today called nouns in English), adjectives (nomen adjectivum) and numerals (nomen numerale). This is reflected in the older English terminology noun substantive, noun adjective and noun numeral. Later the adjective became a separate class, as often did the numerals, and the English word noun came to be applied to substantives only.
Classification Works of English grammar generally follow the pattern of the European tradition as described above, except that participles are now usually regarded as forms of verbs rather than as a separate part of speech, and numerals are often conflated with other parts of speech: nouns (cardinal numerals, e.g., "one", and collective numerals, e.g., "dozen"), adjectives (ordinal numerals, e.g., "first", and multiplier numerals, e.g., "single") and adverbs (multiplicative numerals, e.g., "once", and distributive numerals, e.g., "singly"). Eight or nine parts of speech are commonly listed:
… excerpt ends here. Continue reading the full article.
