In linguistics, a partitive is a word, phrase, or case that indicates partialness. Nominal partitives are syntactic constructions, such as "some of the children", and may be classified semantically as either set partitives or entity partitives based on the quantifier and the type of embedded noun used. Partitives should not be confused with quantitives (also known as pseudopartitives), which often look similar in form, but behave differently syntactically and have a distinct meaning.

In many Romance and Germanic languages, nominal partitives usually take the form: [DP Det. + of + [DP Det. + NP]]Martí i Girbau, M. N. (2010). The syntax of partitives. where the first determiner is a quantifier word, using a prepositional element to link it to the larger set or whole from which that quantity is partitioned. The partitive constructions of the following languages all have the same translation, with a very similar form:

Language Nominal partitive English three of my friends Catalan tres dels meus amics Spanish tres de mis amigos French trois de mes amis Italian tre dei miei amici Portuguese três dos meus amigos Dutch drie van mijn vrienden Swedish tre av mina vänner Greek τρεις από τους φίλους μου

Some languages, for example Estonian, Finnish, and Basque have a special partitive case. In Latin, German and Russian, the partitive is expressed by the genitive case, sometimes called the partitive genitive.Valkova, Z. (1999). Semantics of case: The partitive genitive in russian. ProQuest, UMI Dissertations Publishing).

Set partitives and entity partitives

Partitives can be distinguished semantically based on whether they involve a part of a whole, called entity partitives, or a subset of a larger set, called set partitives. The embedded NPs in entity partitives denote either entities at the individual level, such as "a cookie" or entities at the group level, such as "Bob and Sue". Some phrases such as ‘the linguists’ can be interpreted as either a group level entity and thus participate in an entity partitive – "half of the linguists"; alternatively, it can be interpreted as a set of entities, and thus participate in a set partitive – "one of the linguists".de Hoop, H. (1997). A semantic reanalysis of the partitive constraint. Lingua,103(2), 151-174

Set partitives contain plural countable nouns in their embedded noun phrase (NP), and can be combined with quantifier determiners such as "many", and specific numbers such as "three". Entity partitives can contain either singular countable nouns or mass nouns (and sometimes even plural countable nouns), combining with determiners such as ‘much’, or those with a fractional meaning, like ‘half’. Other determiners can be combined with either type of partitive, including ‘some’, ‘many’, and ‘all’. The following is a list of different quantifier determiners in English and their classification as either participating in entity partitives, set partitives, or both:

Quantifier determiner Type of partitive Example half Entity half of the water; half of the cats 20% Entity 20% of the water; 20% of the cats one third Entity one third of the water; one third of the cats much Entity much of the water; *much of the cats three (or any number) Set three of the cats; *three of the water many Set many of the cats; *many of the water some Ambiguous some of the water; some of the cats all Ambiguous all of the water; all of the cats most Ambiguous most of the water; most of the cats

The partitive constraint

Given the following syntactic structure of partitives, [DP Det. + of + [DP Det. + NP]], the first determiner is a quantifier word which quantifies over a subset or part of the embedded DP, which either denotes a set or a whole respectively. The second determiner is usually an article, a demonstrative, a possessive determiner, or even another quantifier.

Jackendoff proposed a version of the partitive constraint in which the embedded determiner phrase (DP) must be definite, and thus must be headed by a definite determiner, such as "the", "these", or "my".Jackendoff, R., 1977. X-bar syntax: A study of phrase structure. Cambridge, MA: MIT Press.

However, this approach fails to account for phrases such as "half of a cookie," that are partitives and yet lack a definite determiner. De Hoop instead points to the existence of set partitives and entity partitives in formulating the partitive constraint, rather than the definiteness of the NP. She states that:

Only NPs that can denote entities are allowed in entity partitives and only NPs that can denote sets of entities are allowed in set partitives.

1. a) *one of a cookie b) half of a cookie

2. a) *one of the water b) half of the water

(2a) is ungrammatical even though it has a definite article because the denoted entity does not match. "The water" denotes an entity, and "one" is a set entity partitive determiner. (1b) is correct because indefinite and definite singular count nouns denote single entities rather than a set of entities, therefore it is grammatical when proceeded by "half", an entity partitive determiner.

It should also be noted that some linguists consider the partitive constraint to be problematic, since there may be cases where the determiner is not always obligatory. Linguists do, however, agree that universal quantifiers, such as: every, and each, cannot be embedded in the partitive position. Furthermore, the second determiner can be "all" only if the first determiner is a superlative, or fractional expression.

3. a) "The best of all the wines" b) "15% of all the relationships"

It has also been hypothesized that perhaps "of" in sentences, such as the above, do not act as the partitive themselves, but rather the superlative in the sentence provides the role of partition.

Anti-uniqueness

Barker claims that partitives are anti-unique; that is, a partitive cannot refer to a unique individual or set of individuals, but must have at least two individuals or sets of individuals in its extension, causing a degree of indefiniteness.Barker, C. (1998). Partitives, double genitives and anti-uniqueness. Natural Language & Linguistic Theory, 16(4), 679-717.

In addition, he limits a partitive to being only able to refer to a proper subset, which he calls proper partitivity. This means that, for example, in the partitive phrase "one of John’s friends", that John must have at least two friends for this to be a proper partitive, and in order for it to satisfy anti-uniqueness by not referring to a unique individual. Similarly, "three of John’s friends" would imply that John has at least four friends, from which an indeterminate three are being referred to.

4. a) I met [one of John's friends]. b) *I met the [one of John's friends]. c) I met the [one of John’s friends] that you pointed out this morning.

Furthermore, Barker states that DP partitive constructions cannot be headed by a definite determiner without being modified by a relative clause, that there is some inherent indefiniteness in partitives according to their property of anti-uniqueness. This explains why 4b) is ill-formed, since it is unclear which of John’s friends is being singled out, yet can be made to take a definite determiner by adding context, such as in 4c), which now refers to a single specific friend of John matching the modifier clause.

Partitives and quantitatives

A true partitive should be distinguished from a very similar construction called a quantitative (often called a pseudopartitive, or sometimes a non-partitive).

5. a) A box of those chocolates b) A box of chocolates

6. a) *The three of those cars b) The three cars

A true partitive, as shown in 5a), has the interpretation of a quantity being a part or subset of an entity or set. Quantitives, simply denote either a quantity of something or the number of members in a set, and contain a few important differences in relation to true partitives.

First off, while partitives cannot be preceded by a definite determiner, such as in 6a), quantitatives can be; 6b) is a well-formed quantitive.

While the NP in partitives is usually preceded by a definite determiner, the NP in quantitive constructions containing "of" cannot be preceded by any determiner; this distinguishes the true partitive in 5a) from the quantitative in 5b), which denotes a quantity of chocolates, but does not denote a smaller quantity of chocolates taken from a larger quantity of chocolates, as 5a) does.

Quantitives can be interpreted as partitives, though, when modified. Consider the example, "three children in the class"; this means "three children out of the children that are in the class", which has a partitive meaning.Stickney, H. (2007). From pseudopartitive to partitive. In Proceedings of the 2nd Conference on Generative Approaches to Language Acquisition North America (GALANA), Somerville, MA (pp. 406-415).

One point which is important in distinguishing between partitives and pseudopartitives in English is a separation between two semantically different "of"s. The first is a genitive "of", which indicates a kind-of or type-of relation demonstrated in the phrase "a book of history", in which "of" is used to modify the kind of book denoted, alternatively phrased as the compound noun "a history book". Similarly, "a piece of chocolate" can be analyzed as a certain kind of piece, namely a chocolate piece. The second is a partitive "of", which indicates a part-of relation and means "out of the total number of" in the case of set partitives. A partitive like "a piece of this chocolate" does not refer to any chocolate piece, but a piece taken from the whole of a certain chocolate.

Although the syntactic distribution of partitives and pseudo-partitives seems to be complementary, cross-linguistic data suggests this is not always true. Non-partitives can display an identical syntactic structure as true partitives and the ultimate difference is a semantic one. Vos pointed out that Dutch contains nominals fulfilling the syntactic criterion but lacking a partitive interpretation; they are therefore classified as non-partitives.

The first Dutch phrase above is classified as a non-partitive. This is counter-intuitive at first glance because the phrase has a Det+of+Det+N sequence which is a consistent structure observed in partitives. A closer look at the Dutch data reveals that in denoting relativation and extraction relationships, non-partitives (or weak indirect partitive construction in Vos’s terminology) function as an adjectival modifier as opposed to ordinary partitives (strong indirect partitive construction) carrying a determiner-like element. Therefore, diew contains an adjectival meaning closer to 'such' and indicates funny examples of a certain type. In the second example, dies is truly a definite determiner and is referring to a particular larger set of funny examples.

Structural approaches to partitives While a number of linguists have proposed different approaches to account for the partitive structure, three approaches will be introduced here.

A functional projection approach In 1995, Guillermo Lorenzo proposed a partitive (π), which is equivalent to the meaning of "out of" in English, is a functional category by itself and projects to a phrasal level. A partitive phrase (πP) is selected by the Numeral (Num) and in turn the partitive head (π) selects the following DP. A Spanish example is shown below:

8. [NumP muchos [πP de[DP estos [NumP [Num° [libr-i+-os] [NP ti]]]]]] many of these book +s

Partitive prepositional phrase approach Advocates of the partitive prepositional phrase (partitive PP) approach claim that the partitive meaning is integrated into a PP. Structurally, a quantifier is followed by a noun, and a preposition in between denotes the quantifier is a subset of the following noun.