Editing Relative clause (section)

==Accessibility hierarchy==
The antecedent of the relative clause (that is, the noun that is modified by it) can in theory be the subject of the main clause, or its object, or any other [[verb argument]]. In many languages, however, especially rigidly [[left-branching]], [[dependent-marking language]]s with prenominal relative clauses,<ref>{{cite journal |last=Lehmann |first=Christian |date=1986 |title=On the typology of relative clauses |journal=Linguistics |volume=24 |issue=4 |pages=663–680 |doi=10.1515/ling.1986.24.4.663}}</ref> there are major restrictions on the role the antecedent may have ''in the relative clause''.

Edward Keenan and [[Bernard Comrie]] noted that these roles can be ranked cross-linguistically in the following order from most accessible to least accessible:<ref>{{cite journal |last1=Keenan |first1=Edward L. |last2=Comrie |first2=Bernard |date=1977 |title=Noun phrase accessibility and Universal Grammar |journal=[[Linguistic Inquiry]] |volume=8 |issue=1 |pages=63–99}}</ref><ref>{{cite book |last=Comrie |first=Bernard |title=Language Universals and Linguistic Typology |date=1981 |pages=156–163 |publisher=University of Chicago Press |isbn=0-226-11434-1}}</ref>

:Subject > Direct Object > Indirect Object > Oblique > Genitive > Object of comparative

[[Ergative–absolutive]] languages have a similar hierarchy:

:[[Absolutive case|Absolutive]] > [[Ergative case|Ergative]] > Indirect Object > etc. (same as above)

This order is called the '''accessibility hierarchy'''. If a language can relativize positions lower in the accessibility hierarchy, it can always relativize positions higher up, but not vice versa. For example, [[Malagasy language|Malagasy]] can relativize only subject and [[Chukchi language|Chukchi]] only absolutive arguments, whilst [[Basque language|Basque]] can relativize absolutives, ergatives and indirect objects, but not obliques or genitives or objects of comparatives. Similar hierarchies have been proposed in other circumstances, e.g. for pronominal reflexes.

[[English language|English]] can relativize all positions in the hierarchy. Here are some examples of the NP and relative clause usage from English:

{| align="center"
!Position !! With explicit relative pronoun !! With omitted relative pronoun !! In formal English
|-
|[[subject (grammar)|Subject]] || That's the woman [who ran away]. || — || That's the woman [who ran away].
|-
|[[Direct object]] || That's the woman [who I saw yesterday]. || That's the woman [I saw yesterday]. || That's the woman [whom I saw yesterday].
|-
|[[Indirect object]] || That's the person [who I gave the letter to]. || That's the person [I gave the letter to]. || That's the person [to whom I gave the letter]. 
|-
|[[oblique case|Oblique]] || That's the person [who I was talking about].  || That's the person [I was talking about]. || That's the person [about whom I was talking]. 
|-
|[[Genitive]] || That's the woman [whose brother I know].	       || — ||  That's the woman [whose brother I know].
|-
|Obj of Comp || That's the woman [who I am taller than].		       || That's the woman [I am taller than]. || That's the woman [than whom I am taller].
|}

Some other examples:

{| align="center"
!Position !! Example
|-
|[[subject (grammar)|Subject]] || The girl [who came late] is my sister.
|-
|[[Direct object]]  || I gave a rose to the girl [that Kate saw].
|-
|[[Indirect object]] || John knows the girl [I wrote a letter to].
|-
|[[oblique case|Oblique]] || I found the rock [which the robbers had hit John over the head with].
|-
|[[Genitive]] || The girl [whose father died] told me she was sad.
|-
|Obj of Comp || The first person [I can't run faster than] will win a million dollars.
|}

Languages that cannot relativize directly on noun phrases low in the accessibility hierarchy can sometimes use alternative [[grammatical voice|voices]] to "raise" the relevant noun phrase so that it can be relativized. The most common example is the use of [[applicative voice]]s to relativize obliques, but in such languages as Chukchi [[antipassive voice|antipassives]] are used to raise ergative arguments to absolutive.

For example, a language that can relativize only subjects could say this:
*The girl [who likes me] came to visit.
But not:
*The girl [whom I like] came to visit.
*The girl [whom I gave a rose to] came to visit.
*The girl [whom I watched a movie with] came to visit.
*The girl [whose father I know] came to visit.
*The girl [whom I know the father of] came to visit. (''equivalent to previous'')
*The girl [whom I am taller than] came to visit.
These languages might form an equivalent sentence by [[passive voice|passivization]]:
*The girl [who was liked by me] came to visit.
*The girl [who was given a rose by me] came to visit.
*The girl [who was watched a movie with by me] came to visit.
*The girl [who was known the father of by me] came to visit.
*The girl [who was been taller than by me] came to visit.
These passivized sentences get progressively more ungrammatical in English as they move down the accessibility hierarchy; the last two, in particular, are so ungrammatical as to be almost unparsable by English speakers. But languages with severe restrictions on which roles can be relativized are precisely those that can passivize almost any position, and hence the last two sentences would be normal in those languages.

A further example is languages that can relativize only subjects and direct objects. Hence the following would be possible:
*The girl [who I like] came to visit.
The other ungrammatical examples above would still be ungrammatical. These languages often allow an oblique object to be moved to the direct object slot by the use of the so-called ''[[applicative voice]]'', much as the [[passive voice]] moves an oblique object to the subject position. The above examples expressed in an applicative voice might be similar to the following (in not necessarily grammatical English):
*The girl [who I gave a rose] came to visit.
*The girl [who I with-watched a movie] came to visit.
*The girl [who I (of-)know the father] came to visit.
*The girl [who I out-tall] came to visit.

Modern grammars may use the accessibility hierarchy to order productions—e.g. in [[Head-Driven Phrase Structure Grammar]] the hierarchy corresponds to the order of elements on the ''subcat'' list, and interacts with other principles in explanations of binding facts. The hierarchy also figures in
[[Lexical Functional Grammar]], where it is known as Syntactic Rank or the Relational Hierarchy.