Intheoretical linguistics, a distinction is made betweenendocentric andexocentric constructions. Agrammatical construction (for instance, aphrase orcompound) is said to beendocentric if it fulfils the same linguistic function as one of its parts, andexocentric if it does not.[1] The distinction reaches back at least toBloomfield's work of the 1930s,[2] who based it on terms byPāṇini andPatañjali inSanskrit grammar.[3] Such a distinction is possible only inphrase structure grammars (constituency grammars), since independency grammars all constructions are necessarily endocentric.[4]
An endocentric construction consists of an obligatoryhead and one or more dependents, whose presence serves to modify the meaning of the head. For example:
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 syntactic category to which the wholeconstituent will be assigned. The phrasebig house is anoun phrase in line with its parthouse, which is a noun. Similarly,sing songs is averb phrase in line with its partsing, which is a verb. The same is true ofvery long; it is anadjective phrase in line with its partlong, 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 aheaded 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 aphrase structure grammar).[5] The traditional binary division[6] of the sentence (S) into asubjectnoun phrase (NP) and apredicateverb phrase (VP) was exocentric:
Since the whole is unlike either of its parts, it is exocentric. In other words, since the whole is neither a noun (N) likeHannibal nor a verb phrase (VP) likedestroyed Rome but rather a sentence (S), it is exocentric. With the advent ofX-bar theory inTransformational Grammar in the 1970s, this traditional exocentric division was largely abandoned and replaced by an endocentric analysis, whereby the sentence is viewed as aninflection phrase (IP), which is essentially a projection of the verb (a fact that makes the sentence a big VP in a sense). Thus, with the advent of X-bar theory, the endocentric vs. exocentric distinction started to become less important in transformational theories of syntax, for without the concept of exocentricity, the notion of endocentricity was becoming vacuous.
By contrast, inconstraint-basedsyntactic theories, such asLexical Functional Grammar (LFG), exocentric constructions are still widely used, but with a different role. Exocentricity is used in the treatment ofnon-configurational languages. As constraint-based models such as LFG do not represent a "deep structure" at which non-configurational languages can be treated as configurational, the exocentric S is used to formally represent the flat structure inherent in a non-configurational language. Hence, in a constraints-based analysis ofWarlpiri, an exocentric structure follows the auxiliary, dominating all of the verb, arguments and adjuncts which are not raised to the specifier position of the IP:
In addition, in theories ofmorphology, the distinction remains, since certaincompounds seem to require an exocentric analysis, e.g.have-not inBill is a have-not. For a class of compounds described as exocentric, seebahuvrihi.
The endo- vs. exocentric distinction is possible inphrase structure grammars (= constituency grammars), since they are constituency-based. The distinction is hardly present independency grammars, since they are dependency-based. In other words, dependency-based structures are necessarily endocentric, i.e. they are necessarily headed structures. Dependency grammars by definition were much less capable of acknowledging the types of divisions that constituency enables. Acknowledging exocentric structure necessitates that one posit more nodes in the syntactic (or morphological) structure than one has actual words or morphs in the phrase or sentence at hand. What this means is that a significant tradition in the study of syntax and grammar has been incapable from the start of acknowledging the endo- vs. exocentric distinction, a fact that has generated confusion about what should count as an endo- or exocentric structure.
Theories of syntax (and morphology) represent endocentric and exocentric structures using tree diagrams and specific labeling conventions. The distinction is illustrated here using the following trees. The first three trees show the distinction in a constituency-based grammar, and the second two trees show the same structures in a dependency-based grammar:
The upper two trees on the left are endocentric since each time, one of the parts, i.e. the head, projects its category status up to the mother node. The upper tree on the right, in contrast, is exocentric, because neither of the parts projects its category status up to the mother node; Z is a category distinct from X or Y. The two dependency trees show the manner in which dependency-based structures are inherently endocentric. Since the number of nodes in the tree structure is necessarily equal to the number of elements (e.g. words) in the string, there is no way to assign the whole (i.e. XY) a category status that is distinct from both X and Y.
Traditional phrase structure trees are mostly endocentric, although the initial binary division of the clause is exocentric (S → NP VP), as mentioned above, e.g.
This tree structure contains four divisions, whereby only one of these divisions is exocentric (the highest one). The other three divisions are endocentric because the mother node has the same basic category status as one of its daughters. The one exocentric division disappears in the corresponding dependency tree:
Dependency positions the finite verb as the root of the entire tree, which means the initial exocentric division is impossible. This tree is entirely endocentric.
TheChinese language is known for having richcompounds.[7] Linguists often classify compound verbs in Chinese into five types:Subject-Predicate 主謂結構 (SP),Verb-Object 述賓結構 (VO),Verb-Complement 述補結構 (VC),Coordinative 並列結構 (VV), andEndocentric 偏正結構.[8][9] The Coordinative, Verb-Complement, and Endocentric types are also known asParallel,Verb-Resultative, andModifier-Head, respectively.[10]
Below are a few examples of the exocentric compounds in Chinese.[11][12]
| Example | Internal Structure | Explanation |
|---|---|---|
| 大小dà-xiǎo | A-A → N | big + small → size |
| 好歹hǎo-dǎi | A-A → Adv | good + bad → anyhow |
| 開關kāi-guān | V-V → N | open + close → switch |
| 保守bǎo-shǒu | V-V → A | keep + defend → conservative |
| 物色wù-sè | N-N → V | item + color → choose from |
| 矛盾máo-dùn | N-N → A | spear + shield → contradictory |
TheWarlpiri language is widely held as the canonical example of anon-configurational language.[13] As such, Warlpiri sentences exhibit exceptionally flat surface structure. If a non-derivational approach is taken to syntactic structure, this can best be formalised with exocentric S dominated by the auxiliary in I. Thus, an example analysis of the constituent structure of the Warlpiri sentence:
Ngarrka-ngku
man-ERG
ka
wawirri
kangaroo.ABS
panti-rni
spear-NPAST
Ngarrka-ngku ka wawirri panti-rni
man-ERG AUX kangaroo.ABS spear-NPAST
'the man is spearing the kangaroo'
would be as follows:
Where S is a non-projected exocentric structure which dominates both heads and phrases with equal weight. The elements in spec of IP and under S can be freely moved and switch places, as position in c-structure, except for I, plays a pragmatic rather than syntactic role in a constraints-based analysis of Warlpiri sentence structure.
While exocentric structures have largely disappeared from most theoretical analyses of standard sentence structure, many theories of syntax still assume (something like) exocentric divisions forcoordinate structures, e.g.
The brackets each time mark the conjuncts of a coordinate structure, whereby this coordinate structure includes the material appearing between the left-most bracket and the right-most bracket; the coordinator is positioned between the conjuncts. Coordinate structures like these do not lend themselves to an endocentric analysis in any clear way, nor to an exocentric analysis. One might argue that the coordinator is the head of the coordinate structure, which would make it endocentric. This argument would have to ignore the numerous occurrences of coordinate structures that lack a coordinator (asyndeton), however. One might therefore argue instead that coordinate structures like these are multi-headed, each conjunct being or containing a head. The difficulty with this argument, however, is that the traditional endocentric vs. exocentric distinction did not foresee the existence of multi-headed structures, which means that it did not provide a guideline for deciding whether a multi-headed structure should be viewed as endo- or exocentric. Coordinate structures thus remain a problem area for the endo- vs. exocentric distinction in general.