Head-directionality parameter
In linguistics, head directionality is a proposed parameter that classifies languages according to whether they are head-initial or head-final. The head is the element that determines the category of a phrase: for example, in a verb phrase, the head is a verb. Therefore, head initial would be "VO" languages and head final would be "OV" languages.
Some languages are consistently head-initial or head-final at all phrasal levels. English is considered to be mainly head-initial, while Japanese is an example of a language that is consistently head-final. In certain other languages, such as German and Gbe, examples of both types of head directionality occur. Various theories have been proposed to explain such variation.
Head directionality is connected with the type of branching that predominates in a language: head-initial structures are right-branching, while head-final structures are left-branching. On the basis of these criteria, languages can be divided into head-final and head-initial types. The identification of headedness is based on the following:
- the order of subject, object, and verb
- the relationship between the order of the object and verb
- the order of an adposition and its complement
- the order of relative clause and head noun.
Types of phrase
- Verb Phrase: the head of verb phrase is a verb, and the complement are most commonly objects of various types. The ordering here is related to one of the chief questions in the word order typology of languages, namely the normal order of subject, verb and object within a clause.
- Noun Phrase: the head of a noun phrase is a noun; various kinds of complementizer phrases and adpositional phrases can be complements.
- Adjective Phrase: the head of an adjective phrase is an adjective, which can take as a complement, for example, an adverbial phrase or adpositional phrase.
- Adpositional Phrase: the head of an adpositional phrase is an adposition. Such phrases are called prepositional phrases if they are head-initial, or postpositional phrases if they are head-final. The complement is a determiner phrase.
- Determiner Phrase: the head of a determiner phrase is a determiner. DPs were proposed under generative syntax; not all theories of syntax agree that they exist.
- Complementizer Phrase: the head of a complementizer phrase is a complementizer, like that in English. In some cases the C head is covert. The complement of C is generally agreed to be a tense phrase.
- Tense Phrase: the head of a tense phrase is tense; these are phrases in which the head is an abstract category representing tense; the complement is a verb phrase.
- Aspect Phrase: the head of an aspect phrase is aspect; these are phrases in which the head is an abstract syntactic category representing aspect. In more traditional analysis the entire phrase is considered to be simply a verb phrase.
Head-initial languages
English
is a mainly head-initial language. In a typical verb phrase, for example, the verb precedes its complements, as in the following example:The head of the phrase precedes its complement. Switching the order to " V eat" would be ungrammatical.
Nouns also tend to precede any complements, as in the following example, where the relative clause that follows the noun may be considered to be a complement:
Nouns do not necessarily begin their phrase; they may be preceded by attributive adjectives, but these are regarded as adjuncts rather than complements. Adjectives themselves may be preceded by adjuncts, namely adverbs, as in extremely happy. However, when an adjective phrase contains a true complement, such as a [prepositional phrase, the head adjective precedes it:
English adpositional phrases are also head-initial; that is, English has prepositions rather than postpositions:
On the determiner phrase view, where a determiner is taken to be the head of its phrase, English can be seen to be head-initial in this type of phrase too. In the following example the head is taken to be the determiner any, and the complement is the noun book:
English also has head-initial complementizer phrases, as in this example where the complementizer that precedes its complement, the tense phrase Mary did not swim:
Grammatical words marking tense and aspect generally precede the semantic verb. This indicates that, if finite verb phrases are analyzed as tense phrases or aspect phrases, these are again head-initial in English. In the example above, did is considered a tense marker, and precedes its complement, the verb phrase not swim. In the following, has is a aspect marker; again it appears before the verb which is its complement.
The following example shows a sequence of nested phrases in which each head precedes its complement. In the complementizer phrase in, the complementizer precedes its tense phrase complement. In the tense phrase in, the tense-marking element precedes its verb phrase complement. In the verb phrase in, the verb precedes its two complements, namely the determiner phrase the book and the prepositional phrase on the table. In, where a picture is analyzed as a determiner phrase, the determiner a precedes its noun phrase complement, while in, the preposition on precedes its DP complement your desk.
Indonesian
is an example of an SVO head-initial language. The characteristic of it being a head-initial language can be examined through a dependency perspective or through a word order perspective. Both approaches lead to the conclusion that Indonesian is a head-initial language.Dependency perspective
When examining Indonesian through a dependency perspective, it is considered head initial as the governor of both constituents are positioned before the dependent.Placing the head before a dependent minimizes the overall dependency distance, which is the distance between the two constituents. Minimizing dependency distance allows for less cognitive demand as a head-final dependency requires the constituents in the dependent clause to be stored in working memory until the head is realized.
In Indonesian, the number of constituencies affects the dependency direction. When there are 6 constituents — which is a relatively short sentence — there is a preference for head initial relation. However, when there are 11-30 constituents, there appears to be a balance of head-initial and head-final dependencies. Regardless, Indonesian displays an overall head-initial preference on all levels of dependency structure as it consistently attempts to position the head as early on in the sentence even though it produces a longer dependency distance rather than placing the head after its dependents. Furthermore, Indonesian has an overall preference towards head-initial when comparing head-initial and head-final relation on all levels of constituent length for both spoken and written data.
Word order perspective
The subject of the sentence followed by the verb, representing SVO order. The following examples demonstrate head-initial directionality in Indonesian :In Indonesian a noun can be followed by another modifying noun whose primary function is to provide more specific information about the preceding head noun, such as indicating what the head noun is made of, gender, locative sense, and what the head noun does, etc. However, no other word is able to intervene between a head noun and its following modifying noun. If a word follows the modifying noun, then it provides reference to the head noun and not the modifying noun.
- Head noun: + Modifying noun:
- Head noun: + Modifying noun: + Determiner
- Head noun: + Modifying noun:
- Head noun: + Modifying noun: + Determiner phrase
- Head noun: + Modifying noun:
Head-final languages
Japanese
is an example of a strongly head-final language. This can be seen in verb phrases and tense phrases: the verb comes after its complement, while the tense marker comes after the whole verb phrase which is its complement.C ''''''