Optimal word order

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Optimal word order

• Constraint-based linearization of multi-dominant
  dependency structures

2
Structures and strings

• Structures represent syntactic and semantic
  relations between words.
• Strings do not consistently represent syn/sem
  relations
• unrelated neighbors
• George bought a new camel.
• related non-neighbors
• George bought a new camel.
• We hear strings, not structures.
• Strings are predictable from structures.

3
Phrase-structure trees represent dominance
precedence. Strings represent precedence.

George
bought
a
camel
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Structures and strings

• Scenario I
• Structures exhaustively specify precedence
  relations. Strings are simply lower-dimensional
  projections of structures.
• Scenario II
• Structures specify some precedence relations.
  Strings observe these specifications
  linearization specifications of a PF component.
• a asymmetrically c-commands b ? a precedes b,
• but sister order unspecified
• Scenario III
• Structures do not specify any precedence
  relations. String is read off via some
  linearization procedure.

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Grammar
Structure
Linearization Procedure
String
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(No Transcript)
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Word Order Optimization

• Gen produces possible strings for any given
  structure

• Linearization constraints determine the optimal
  string corresponding to the stricture
• Ranking produce different linearization for the
  same structure across languages

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Structures
Grammar
Structure
Word Order Optimization

• Dependency structures
• specify only head-dependent relationship

String
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Grammar
Grammar
Structure

• A dependency grammar specifies
• Possible heads for each word/category

Word Order Optimization
String

• Subcat frames for each word/category
• Constraints on structure
• single root
• only one word with null head
• no cycles
• no word is directly/indirectly self-dependent

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Grammatical Roles

• May be configurationally defined or substantively
  annotated

bought
subj
obj
George
camel
a
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Constraints

• May refer to
• (dis)preferred alignment within the string
• beginning, center, edge, end
• (dis)preferred local alignment of head wrt
  dependents
• (dis?)preferred adjacency
• relative order
• externally motivated, e.g. prominence scale

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Deriving base word order

• Greenbergs WO Universals
• Universal 1. In declarative sentences with
  nominal subject and object, the dominant order is
  almost always one in which the subject precedes
  the object.
• Assume that SVO, SOV, VSO are possible base word
  orders
• Prohibit all other word orders
• OSV, OVS, VOS

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Deriving base word order

• DeclTopS Subject is default topic in
  declarative sentences
• Prom SgtgtO More prominent elements precede less
  prominent elements (cf. Aissens Relational
  scale)
• VgtgtO verb precedes objects (partially a version
  of HeadLeft)
• VHeadEdge verb head must be at the edge of its
  dependents (all dependents must be on one
  side)(cf. Zepters LexHeadEdge)

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Deriving WO with auxiliary verb

• Greenbergs WO Universals
• Universal 16. In languages with dominant order
  VSO, an inflected auxiliary always precedes the
  main verb. In languages with dominant order SOV,
  an inflected auxiliary always follows the main
  verb.
• Typology
• VSO / AuxVSO
• SOV /SOVAux
• SVO / SAuxVO ??

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Deriving WO with auxiliary verb

• 24 permutations possible for V, Aux, S, O
• 21 of them never occur
• Must maintain base order constraints
• Greenbergs generalization suggests
  language-particular order depends on base order

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Deriving WO with auxiliary verb

• Current constraints 1 new constraint exclude
  all 21 undesirable outputs as harmonically bound.
  
• New constraint
• Aux and verb must be adjacent
• Formulated as generally as possible
• DH Dependent must be adjacent to head or to
  its sister dependents

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Aux
V
S
O
Assume structural subject dependent on Aux and
Verb
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Deriving WO with auxiliary verb

• Base-order dependence falls out of the analysis
• Ranking which produces SVO also produces
  exclusively SAVO
• Ranking which produces SOV also produces
  exclusively SOVA
• Ranking which produces VSO also produces
  exclusively AVSO
• DH discriminates against other undesirable
  candidates

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Deriving WO of questions

• Incomplete (?) typology
• base/auxQ/baseQ
• SVO/ASVO/ASVO English
• SVO/AVSO/VSO Bulgarian
• SOV/AVSO/VSO Latin
• VSO/AVSO/VSO

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Deriving WO of questions

• DecTopS is vacuously satisfied (active only in
  declaratives)
• Oops in this case, only possible question
  orders are AVSO and VSO
• How do we obtain English ASVO, ASVO?
• Or even Bulgarian AVSO/VSO?
• In situ questions?

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Deriving WO of questions

• Two issues Aux epenthesis (English)
  Faithfulness to base word order (In situ)
• Auxiliary epenthesis is not universal. ? Some
  constraint discriminates against it.
• EpAux
• In situ questions FaithBaseOrder
• In situ questions introduce ambiguity MarkQ

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Deriving WO of questions SVO

• We now have 8 constraints, 40320 grammars, but
  only 4 question orders given FaithBaseSVO
• SVO/SAVO/VSO/AVSO (Bulgarian)
• SVO/SAVO/VSO/ASVO (French)
• SVO/SAVO/SVO/ASVO (English-epenthesis)
• SVO/SAVO/ASVO/ASVO (English)

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Deriving WO of questions SOV

• We now have 8 constraints, 40320 grammars, but
  only 4 question orders given FaithBaseSOV
• SOV/SOVA/VSO/AVSO
• SOV/SOVA/VSO/ASOV
• SOV/SOVA/SOV/ASOV
• SOV/SOVA/ASOV/ASOV

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Deriving WO of questions VSO

• We now have 8 constraints, 40320 grammars, but
  only 1 question orders given FaithBaseVSO
• VSO/AVSO/VSO/AVSO

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Conclusion

• Underlying (multi-headed) dependency structures
  can be linearized using a restricted set of
  constraints formulated from general templates
  observing locality
• Resulting linearization typologies closely
  conform to Greenbergs observations
• Future questions
• Are input structures universal or OT-outputs?
• Are all permutations considered or is Gen a
  restricted read-off procedure?

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References

• Aissen, J. (1999) Markedness and Subject Choice
  in Optimality Theory. Natural Language
  Linguistic Theory 17 673-711.
• Greenberg, J.H. 1966. Universals of Language.
  Cambridge. The M.I.T. Press
• Grimshaw, Jane. (1997). Projection, Heads, and
  Optimality. Linguistic Inquiry 28.3, 373-422.
• Mel'cuk I., Dependency Syntax Theory and
  practice, SUNY Press, Albany, 1988.
• Prince, A P. Smolensky (1993) Optimality
  Theory Constraint Interaction in Generative
  Grammar. Rutgers University Center for Cognitive
  Science Technical Report 2.
• Zepter, A. (2003) Phrase-structure direction
  Having a few choices. PhD, Rutgers Univ.