Head Directionality

Definition:

Head directionality (or the head parameter) is a syntactic parameter that determines whether the head of a phrase — the element that defines the phrase type — precedes (head-initial) or follows (head-final) its complement. In English (head-initial), a verb precedes its object (eat rice), a preposition precedes its NP (in the house), and a noun precedes its PP complement (a book about language). In Japanese (head-final), the verb follows (ご飯を食べる “rice-ACC eat”), a postposition follows its NP (家に “house-at”), and the complement precedes the head noun. Head directionality is part of the parameter-setting framework in Universal Grammar and correlates strongly with the SOV/SVO word order distinction.

Head-Initial vs. Head-Final: Examples

The consistent alignment across all phrase types in a language is called head-consistent or harmonic ordering.

The Head Parameter and Greenberg’s Universals

Greenberg (1963) observed strong statistical correlations between basic word order and other grammatical properties:

• SOV languages tend to: use postpositions, have auxiliary verbs after main verbs, use genitive before noun, have relative clauses before noun
• SVO languages tend to: use prepositions, have auxiliary before main verb, use genitive after or before noun (more variable)

These correlations are captured in principles like the Final Affix Constraint and various parametric accounts of head-directionality.

Theoretical Background

In Government and Binding / Minimalist syntax (Chomsky, 1981; Travis, 1984), head directionality is formalized as whether a head assigns Case to the left or right, or whether complement-specifier ordering is inverted. Baker (2001)’s Atoms of Language presents head directionality as one of a small set of syntactic parameters that, once set, predict a cascade of other grammatical properties.

Head Directionality and L2 Acquisition

Systematic transfer errors from L1 head directionality:

• SOV (Japanese/Korean) ? SVO (English): Early errors where learners place the verb at the end of phrases; objects before verbs; relative clauses before nouns
• SVO (English) ? SOV (Korean/Japanese): Learners tend to place verbs before objects in early production (学生は [verb] 日本語を transitional order)
• Deep acquisition of consistent head-final ordering in Japanese is particularly challenging for head-initial L1 learners — relative clauses before nouns are typologically marked and acquired late

History

The head parameter was formally proposed by Travis (1984) and elaborated in Baker (2001). Chomsky’s Government and Binding framework (1981) provided the theoretical context. Earlier, Greenberg’s (1963) universals had documented the correlations empirically, and they have been revisited and partially confirmed/disconfirmed in subsequent large-scale typological databases (Dryer, 2013 in WALS).

Common Misconceptions

• “All head-final languages are strictly head-final in all phrases” — Even highly head-final languages like Japanese have some head-initial structures (question particles, certain auxiliary constructions)
• “Head directionality and word order are the same” — Head directionality is a more principled theoretical concept; SVO/SOV describes surface order, which follows from head directionality plus other parameters

Criticisms

• The head parameter as a single binary switch is likely too simple — even Baker (2001) treats it as one of several interacting parameters, and typological exceptions are common

Social Media Sentiment

Head directionality provides the theoretical explanation behind “why does Japanese have the verb at the end” — a question that comes up constantly in Japanese learner communities. Last updated: 2026-04

Practical Application

• Frame head directionality explicitly for learners moving between head-initial and head-final L2s: “In Japanese, what you would say last in English, you say first”
• Relative clause structure in Japanese is particularly challenging for English speakers — it appears before the noun, in the opposite order from English

Related Terms

• Word Order
• Parameter Setting
• Pro-Drop
• Universal Grammar
• Syntax
• Scrambling

See Also

• Sakubo

Research

• Travis, L. (1984). Parameters and Effects of Word Order Variation. MIT dissertation. — Proposed the head parameter formally within Government & Binding Theory.
• Baker, M. C. (2001). The Atoms of Language. Basic Books. — Trade-level treatment of syntactic parameters including head directionality.
• Greenberg, J. H. (1963). Some universals of grammar with particular reference to the order of meaningful elements. In J. H. Greenberg (Ed.), Universals of Language. MIT Press. — Empirical correlations underpinning the head-directionality account.