DETERMINER A PART OF SPEECH or word class that determines or limits a noun phrase, showing whether a phrase is definite (the, this, my), indefinite (a, some, much), or limiting it in some other way, such as through negation (no in no hope). Determiners include the articles and words traditionally classified as kinds of adjective or pronoun. They precede adjectives: many clever people, not *clever many people; my poor friend, not *poor my friend. Most words that function as determiners can be used alone as pronouns (this in Look at this picture and Look at this) or have related pronouns (every/everyone/everything, my/mine, no/none). Some grammarians regard as determiners such phrases as plenty of … in We have plenty of money.

Determiners can be subdivided into three groups according to their position in the noun phrase: (1) Central determiners. These may be articles (a, the in a storm, the weather), demonstratives (this, those in this day, those clouds), possessives (my, your in my hat, your umbrella), some quantifiers (each, every, no, any, some in each moment, every day, no excuse, any help, some clouds). Such determiners are mutually exclusive and contrast with adjectives, with which however they can cooccur: the best weather, any possible help, no reliable news. (2) Post-determiners. These are used after central determiners and including numbers (two, first in those two problems, my first job) and some quantifiers (many, several in your many kindnesses, his several attempts). (3) Pre-determiners. These are used before central determiners, mainly referring to quantity. They include: all, both, half (all this time, both your houses, half a loaf), double, twice and other multiplier expressions (double the money, twice the man he was, once each day, six times a year), fractions (a quarter of the price), and such and what in exclamations (Such a waste of money!, What a good time we had!).

They can also be divided according to the countability of the nouns they co-occur with: (1) With singular countable nouns only: a/an, each, every, either, neither. (2) With singular countable and with uncountable nouns: this, that. (3) With uncountable nouns only: much and little/a little, and usually less, least. (4) With uncountable and with plural countable nouns: all, enough, more, most, a lot, lots of, and the primary meaning of some, any. (5) With countable plurals only: a few, few, fewer, fewest, both, many, several, these, those, and numbers. (6) with most common nouns: the, no, the possessives my, your, etc., and some wh- words (whose roll/rolls/bread, by which date, whatever food you eat).

de·ter·min·er / diˈtərminər/ • n. 1. a person or thing that determines or decides something.2. Gram. a modifying word that determines the kind of reference a noun or noun group has, for example a, the, every. See also definite article, indefinite article.