Editing Japanese grammar (section)

===Word order: head-final and left-branching===
The modern theory of constituent order ("word order"), usually attributed to [[Joseph Harold Greenberg]], identifies several kinds of phrases. Each one has a '''head''' and possibly a modifier. The head of a phrase either precedes its modifier (head-initial) or follows it (head-final). Some of these phrase types, with the head marked in boldface, are:
*genitive phrase, i.e., noun modified by another noun ("the '''cover''' of the book", "the book's '''cover'''");
*noun governed by an [[Preposition and postposition|adposition]] ("'''on''' the table", "'''underneath''' the table");
*comparison ("[X is] '''bigger''' than Y", i.e., "compared to Y, X is '''big'''").
*noun modified by an adjective ("black '''cat'''").

Some languages are inconsistent in constituent order, having a mixture of head-initial phrase types and head-final phrase types. Looking at the preceding list, English for example is mostly head-initial, but nouns follow the adjectives which modify them. Moreover, genitive phrases can be either head-initial or head-final in English. By contrast, the Japanese language is consistently head-final:
*genitive phrase:
{{fs interlinear|lang=ja|indent=3
|猫 の '''色'''
|neko no '''iro'''
|cat GEN color
|"the cat's ({{transliteration|ja|neko no}}) '''color''' ({{transliteration|ja|iro}})"}}
*noun governed by an ''adposition'':
{{fs interlinear|lang=ja|indent=3
|日本 '''に'''
|nihon '''ni'''
|Japan in
|"'''in''' Japan"}}
*comparison:
{{fs interlinear|lang=ja|indent=3
|Y より '''大きい'''
|Y yori '''ookii'''
|{{no gloss|Y}} than big
|"'''big'''ger than Y"}}
*noun modified by an adjective:
{{fs interlinear|lang=ja|indent=3
|黒い '''猫'''
|kuroi '''neko'''
|black '''cat'''|}}

Head-finality in Japanese sentence structure carries over to the building of sentences using other sentences. In sentences that have other sentences as constituents, the subordinated sentences (relative clauses, for example), always precede what they refer to, since they are modifiers and what they modify has the syntactic status of phrasal head. Translating the phrase "the man who was walking down the street" into Japanese word order would be "street down walking was man".{{efn|Note that Japanese has no articles, and the different word order obviates any need for the relative pronoun ''who''.}}

Head-finality prevails also when sentences are coordinated instead of subordinated. In the world's languages, it is common to avoid repetition between coordinated clauses by optionally deleting a constituent common to the two parts, as in "Bob bought his mother some flowers and his father a tie", where the second ''bought'' is omitted. In Japanese, such "gapping" must proceed in the reverse order: "Bob mother for some flowers and father for tie bought". The reason for this is that in Japanese, sentences (other than occasional inverted sentences or sentences containing afterthoughts) always end in a verb (or other predicative words like adjectival verbs, adjectival nouns, auxiliary verbs)—the only exceptions being a few sentence-ending particles such as {{transliteration|ja|ka}}, {{transliteration|ja|ne}}, and {{transliteration|ja|yo}}. The particle {{transliteration|ja|ka}} turns a statement into a question, while the others express the speaker's attitude towards the statement.