A classifier, in Broadly conceived, linguistics is the study of human language, and a linguist is someone who engages in this study. ...linguistics, is a Word can mean one of several things: A linguistic word—a unit of language that symbolizes or communicates a meaning, consisting of one or more morphemes. ...word or In Linguistics, a morpheme is the smallest meaningful unit in a given language. ...morpheme used in some languages in certain contexts to indicate the word class of a A noun, or noun substantive, is a word or phrase that refers to a person, place, thing, event, substance or quality. ...noun. Such noun classes are usually defined in part by semantic features (such as shape, animacy, etc.).

A classifier system is not the same as a In linguistics, grammatical genders, also called noun classes, are classes of nouns reflected in the behavior of associated words; every noun must belong to one of the classes and there should be very few which belong to several classes at once. ...grammatical gender system.

• Classifier systems typically involve 20 or more classifiers (separate Definition A lexeme is a unit of linguistic analysis. ...lexemes that co-occur with the noun), while gender systems vary from two to twenty classes at most.
• Not every noun must take a classifier, and many nouns can occur with more than one classifier. (In a gender system, most nouns typically occur with one and only one gender.)
• The classifier occurs in only some In linguistics, syntax is the study of the rules, or patterned relations, that govern the way the words in a sentence come together. ...syntactic environments. In addition, use of the classifier may be influenced by the pragmatics of style and the choice of written or spoken mode. (Often, the more formal the style, the richer the variety of classifiers used, and the higher the frequency of their use.)
• Noun classifiers are always free lexical items that occur in the same noun phrase as the noun they qualify. They never form a Morphology is a subdiscipline of linguistics that studies word structure. ...morphological unit with the noun, and there is never Look up Agreement in Wiktionary, the free dictionary An agreement may be an agreement in beliefs, rules, practices (policies), or conduct. ...agreement marking on the 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. ...verb.
• Noun classifiers are usually derived from words used as names of concrete, discrete, moveable objects.

Examples of languages with noun classifiers are The Japanese language is a spoken and written language used mainly in Japan. ...Japanese, Chinese (written) language (pinyin: zhōngw n) written in Chinese characters The Chinese language (汉语/漢語, 华语/華語, or 中文; Pinyin: H nyǔ, Hu yǔ, or Zhōngw n) is a member of the Sino-Tibetan family of languages. ...Chinese, Southeast Asian languages, The Austronesian languages are a family of languages widely dispersed throughout the islands of Southeast Asia and the Pacific, with a few members spoken on continental Asia. ...Austronesian languages, and The Mayan languages are a family of related languages spoken from South-Eastern Mexico through northern Central America as far south as Honduras. ...Mayan languages.

Usage

Classifiers are most often used when counting. Their use is thus analogous to The English language is a West Germanic language that originates in England. ...English words that represent units or portions of In English, a mass noun is a type of noun that has a singular, but no plural form. ...mass nouns, for example one drop of milk, fifty head of cattle, three pieces of cake. This particular type of classifier is called a Measure words, in linguistics, are words (or morphemes) that are used in combination with a numeral to indicate the count of nouns. ...measure word, as well as a counter or counting word.

It must be noted that not all classifiers are strictly measure words. In Chinese, for example, classifiers are also used with determiners such as "this", "that", etc.

References:

• SIL: Glossary of Linguistic Terms: What is a noun class? (http://www.sil.org/linguistics/GlossaryOfLinguisticTerms/WhatIsANounClass.htm)

See also:

• Measure words, in linguistics, are words (or morphemes) that are used in combination with a numeral to indicate the count of nouns. ...Measure word
• In linguistics, grammatical genders, also called noun classes, are classes of nouns reflected in the behavior of associated words; every noun must belong to one of the classes and there should be very few which belong to several classes at once. ...Grammatical gender