Word classes and phrase classes

Seven major word classes are described here. These are: noun, verb, adjective, adverb, preposition, conjunction, and determiner. The first six are traditionally referred to as "parts of speech." There are minor word classes, such as interjections, but these do not fit into the clause and sentence structure of English.

Open and closed classes

Open word classes allow new members; closed word classes seldom do.Nouns such as "celebutante", (a celebrity who frequents the fashion circles)" and "mentee," (a person advised by a mentor) and adverbs such as "24/7" ("I am working on it 24/7") are relatively new words; nouns and adverbs are therefore open classes.[1] However, invented pronouns, such as the "Spivak pronouns", as a gender-neutral singular replacement for the "his or her" (as in: "The student should bring eir books.") have gained only niche acceptance during their existence; pronouns, in consequence, form a closed class.
Word classes and grammatical forms

A word can sometimes belong to several word classes. The class version of a word is called a "lexeme". For example, the word "run" is usually a verb, but it can also be a noun ("It is a ten mile run to Tipperary."); these are two different lexemes.[2] Further, the same lexeme may be inflected to express different grammatical categories: for example, as a verb lexeme, "run" has several forms such as "runs," "ran," and "running."[ Words in one class can sometimes be derived from those in another and new words be created. The noun "aerobics," for example, has recently given rise to the adjective "aerobicized" ("the aerobicized bodies of Beverly Hills celebutantes."

Phrase classes

Words combine to form phrases which themselves can take on the attributes of a word class. These classes are called phrase classes.[2] The phrase: "The ancient pulse of germ and birth" functions as a noun in the sentence: "The ancient pulse of germ and birth was shrunken hard and dry." (Thomas Hardy, The Darkling Thrush) It is therefore a noun phrase. Other phrase classes are: verb phrases, adjective phrases, adverb phrases, prepositional phrases, and determiner phrases.