In linguistics, a lexical word belongs to one of the "open" parts of speech, such as nouns, verbs, and adjectives. People coin new lexical words all the time, which is what is meant by "open": Open to new additions. A noun, or noun substantive, is a word or phrase that refers to a person, place, thing, event, substance or quality. ... A verb is a part of speech that usually denotes action (bring, read), occurrence (to decompose (itself), to glitter), or a state of being (exist, live, soak, stand). Depending on the language, a verb may vary in form according to many factors, possibly including its tense, aspect, mood and voice. ... An adjective is a part of speech which modifies a noun, usually making its meaning more specific. ... Words and phrases are often created, or coined, by combining existing words, or by giving words new and unique suffixes and/or prefixes. ...

This contrasts with grammatical words, which belong to "closed" parts of speech such as pronouns, numerals, and prepositions. We have only to consider the lack of success of people trying to coin a gender neutral pronoun for English to recognize that such parts of speech are generally "closed" to conscious manipulation, although of course they do change through the unconscious evolution of the language. In linguistics, a grammatical word belongs to one of the closed parts of speech such as pronouns, numerals, and prepositions, which do not readily admit new members. ... In linguistics and grammar, a pronoun is a pro-form that substitutes a noun or noun phrase with or without a determiner, such as you and they in English. ... A numeral is a symbol or group of symbols that represents a number. ... In grammar, a preposition is a type of adposition, a grammatical particle that establishes a relationship between an object (usually a noun phrase) and some other part of the sentence, often expressing a location in place or time. ... In non-sexist language, gender-neutral or epicene pronouns neither reveal nor imply sex or gender when referring to people, animals or things. ...

Lexical and grammatical words often behave differently. Often grammatical words to not make full use of all the sounds in a language. For example, in some of the Khoisan languages, most lexical words begin with clicks, but very few grammatical words do. In Mandarin Chinese, many grammatical words lack tone, but every lexical word has a tone. Map showing the distribution of the Khoi-San languages. ... Clicks are stops produced with two articulatory closures in the oral cavity. ... This article is on all of the Northern Chinese dialects. ... This article or section uses Ruby annotation. ...

See also lexeme Definition A lexeme is an abstract unit of morphological analysis in linguistics, that roughly corresponds to a set of words that are the same in basic meaning. ...