Endocentric and exocentric

In theoretical linguistics, a distinction is made between endocentric and exocentric constructions. A grammatical construction (for instance, a phrase or compound) is said to be endocentric if it fulfils the same linguistic function as one of its parts, and exocentric if it does not. The distinction reaches back at least to Bloomfield's work of the 1930s, who based it on terms by Pāṇini and Patañjali in Sanskrit grammar. Such a distinction is possible only in phrase structure grammars (constituency grammars), since in dependency grammars all constructions are necessarily endocentric. An endocentric construction consists of an obligatory head and one or more dependents, whose presence serves to modify the meaning of the head. For example: [NP [A big] [N house]] [VP [V sing] [N songs]] [AP [Adv very] [A long]] These phrases are indisputably endocentric. They are endocentric because the one word in each case carries the bulk of the semantic content and determines the grammatical category to which the whole constituent will be assigned. The phrase big house is a noun phrase in line with its part house, which is a noun. Similarly, sing songs is a verb phrase in line with its part sing, which is a verb. The same is true of very long; it is an adjective phrase in line with its part long, which is an adjective. In more formal terms, the distribution of an endocentric construction is functionally equivalent, or approaching equivalence, to one of its parts, which serves as the center, or head, of the whole. An endocentric construction is also known as a headed construction, where the head is contained "inside" the construction. An exocentric construction consists of two or more parts, whereby the one or the other of the parts cannot be viewed as providing the bulk of the semantic content of the whole. Further, the syntactic distribution of the whole cannot be viewed as being determined by the one or the other of the parts. The classic instance of an exocentric construction is the sentence (in a phrase structure grammar).