In traditional grammar, a part of speech (abbreviated form: PoS or POS) is a category of words (or, more generally, of lexical items) which have similar grammatical properties. Words that are assigned to the same part of speech generally display similar behavior in terms of syntax—they play similar roles within the grammatical structure of sentences—and sometimes in terms of morphology, in that they undergo inflection for similar properties. Commonly listed English parts of speech are noun, verb, adjective, adverb, pronoun, preposition, conjunction, interjection, and sometimes numeral, article, or determiner. Other Indo-European languages also have essentially all these word classes; one exception to this generalization is that most Slavic languages as well as Latin and Sanskrit do not have articles. Beyond the Indo-European family, such other European languages as Hungarian and Finnish, both of which belong to the Uralic family, completely lack prepositions or have only very few of them; rather, they have postpositions. 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 functional, 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 (like 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 (not to be confused with the seven types of English adjectives, or the fact that English adjectives can modify both nouns and pronouns); Chinese, Korean, Japanese and Vietnamese have a class of nominal classifiers; and 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.
This table shows the example usage of word lists for keywords extraction from the text above.
|Word||Word Frequency||Number of Articles||Relevance|