Presentation on theme: "Exploring Multidominance in Tree Adjoining Grammar Joan Chen-Main Department of Cognitive Science Johns Hopkins University."— Presentation transcript:
Exploring Multidominance in Tree Adjoining Grammar Joan Chen-Main Department of Cognitive Science Johns Hopkins University
In Two Places at Once Some constructions seem like they have an element in two places at once: Joe bakes ___ and Sam eats cookies. What did Emmy eat ___?
Standard Treatment: Trees Movement or ellipsis Unique node immediately dominating each node
Alternative Treatment: Graphs One element in one place Mulitidominance Gärtner, Wilder, Abels, Goodall, and others
How are such graphs generated? What introduces multidominance into the system?
Sarkar and Joshi (1996) Some nodes are marked for contraction and
Sarkar and Joshi (1996) Node contraction results in multidominance and
Example: Conjoined VPs Elementary trees VP BP VP B and
Example: Conjoined VPs VP coordination tree adjoined into eats tree drinks tree substituted into coordination tree
Example: Conjoined VPs NP nodes contract
Example: Conjoined VPs Joe eats cookies and drinks tea.
Pushing the Proposal Instead of being restricted to coordination... Suppose node contraction is a general mechanism in the TAG system. Where else might we see multidominance?
Overview What such a system can do –Coordination –“Movement” –Interleaving –Factoring out recursion Appropriate Restrictions –Island Constraints –Part of Coordinate Structure Constraint Current Concerns –Linearization, Gapping, other part of CSC
Multidomination in “Movement” P ROPOSAL : Node contraction can replace elementary tree internal movement.
Example: Wh-Question Did-eat tree substitutes into wh-question tree
Example: Wh-Question DPs substitutes in to yield What did Emmy eat?
The Interleaving Problem Does Sam seem to like pizza?
Allowing Interleaving Elementary trees marked for node contraction
Allowing Interleaving The does seem tree adjoins into the to like tree
Allowing Interleaving The to like tree substitutes into the yes-no question tree
Hegarty (1993): Smaller trees allow further “Factoring out” of recursive structure –V, I, and some C’s not distinguished by the combinatory operations Small Trees and Recursion
Head Movement in Hegarty’s system requires “hiccup,” two V positions. With node contraction, we can maintain parallel between Eng and French. –Schematic for V to I movement Small Trees and Node Contraction yields
Island Constraints Certain syntactic configurations block movement. (Ross 1967) –embedded questions –wh-relative clauses –subject islands –complex NPs Coordinate Structure Constraint –Part A: No conjunct can be a gap –Part B: No element of a conjunct can be a gap if its filler is outside the conjunct
A Graph To Ban
Deriving Island Effects Impose a restriction on node contraction: After substitution, every node marked for contraction must have been contracted. No such restriction following adjoining Imposes some locality on node contraction Intuition: pieces of structure combined via substitution are somehow more distinct than pieces of structure combined via adjunction.
Locality on Node Contraction A B C X * SchematicDerivation Trees OKnot OK X Tree B Tree C Tree A X Tree B Tree C Tree A
Example: Embedded Question Islands Elementary trees marked for contraction: * Which party did Alice ask who you had invited to?
Example: Embedded Question Islands Problematic to combine these trees: * Which party did Alice ask who you had invited to?
The Unavoidable Problem In the best case scenario... –The to-tree adjoins into the had invited tree. –Following adjoining, nodes waiting to be contraction are allowed.
The Unavoidable Problem –Next, the had invited tree substitutes into the question tree. –Following substitution, no contraction nodes are allowed to be “leftover.” no way for all the nodes marked for contraction to do so.
Failed Derivation * Which party did Alice ask who you had invited to? *
Additional Island Effects This restriction blocks extraction from: –embedded questions –wh-relative clauses –subject islands –complex NPs
Coordinated DPs and the CSC Joe watched a movie about Stevie Wonder and a TV show about bridges.
Coordinated DPs and the CSC * *Who did Joe watch a movie about ___ and a TV show about bridges?
Coordinated DPs and the CSC * What did Joe watch a movie about Stevie Wonder and ___?
Conclusions Allowing general node contraction in TAG: Provides a unified mechanism for coordination and movement (sans traces) Allows derivation of constructions with interleaved elements Allows further factoring out of recursion Can be restricted to derive island effects
Current Concerns Linearization How do we pronounce these graphs? Gapping How do we generate two argument structures from one verb? Coordinated TPs and the Coordinate Structure Constraint
Linearization: elementary trees Elementary trees are indeed trees (and not graphs!). The primitive relations are immediate dominance and sister precedence. Sister precedence is not sensitive to segment/category distinction. –E.g. the lower segment of XP1 sister precedes BP XP1 XP2 BP XP1 B
Linearization: derived trees Each elementary tree contributes immediate dominance and sister precedence information about the derived tree. In the finished graph, –Dominance relation: the transitive closure of available dominance information –Precedence relation: derived from a modified non-tangling condition which uses notion of full dominance.
Linearization: derived trees Full-dominance “non-tangling” condition: If α sister-precedes β, then everything α fully dominates precedes everything β fully dominates. Full-dominance: α fully dominates γ iff every path from γ to the root of the sentence includes α. (Wilder 2001)
Simple Case: Shared Subject Joe eats cookies and ___ drinks tea. * ___ eats cookies and Joe drinks tea. SP’s affecting the contracted node: DP S SP V1` Joe >> eats, cookies DP S SP V2` Joe >> drinks, tea
Simple Case: Shared Subject Joe eats cookies and ___ drinks tea. * ___ eats cookies and Joe drinks tea. Other SP’s will order remaining items: VP1 SP BP eats, cookies >> and, drinks, tea B SP VP2 and >> drinks, tea (VP2 ¬fully dominate Joe.) V1 SP DP1 eats >> cookies V2 SP DP2 drinks >> tea
Simple Case: Right Node Raising Joe bakes ____ and Sam decorates cookies. * Joe bakes cookies and Sam decorates ____. SP’s affecting the contracted node: V1 SP DP O bakes >> cookies V2 SP DP O decorates >> cookies Contrasts with Pronounce-in-Highest- Position strategy
Simple Case: Shared Subj & Obj Joe bakes ____ and ___ decorates cookies. * Joe bakes cookies and ___ decorates ___. * ___ bakes ___ and Joe decorates cookies. * ___ bakes cookies and Joe decorates ___.
Simple Case: Shared Subj & Obj SP’s affecting the contracted nodes: DP S SP V1' Joe >> bakes DP S SP V2' Joe >> decorates V1 SP DP O bakes >> cookies V2 SP DP O decorates >> cookies SP’s ordering remaining items: VP1 SP BP bakes >> and B SP VP2 and >> decorates Contrasts with Wilder’s full- dominance LCA
Kayne’s (1994) LCA If a syntactic structure cannot provide the information needed to linearize its terminals, the structure is ill-formed. Two kinds of violation –Antisymmetry –Totality
Antisymmetry Violations What did Emmy ___ eat ___? Symmetrical Pair: DP O SP QC' what >> eat, did, Emmy V SP DP O eat >> what
Avoiding Symmetry Dominance provides a partial order on SP pairs Give priority to information from the SP pair ordered earliest. –If a contradiction arises later, ignore it. –i.e. If you can’t preserve order, pronounce as high as you can.
Avoiding Symmetry What did Emmy ___ eat ___? Symmetrical Pair: DP O SP QC' what >> eat, did, Emmy V SP DP O eat >> what
Totality Violations John and Mary ate cookies. John, Mary, and and are all unordered wrt ate and cookies.
Coordinated Subjects John and Mary ate cookies. Need such a structure for sentences like: John and Mary met in the park.
Contraction of V', V, & DP John and Mary ate cookies. Could allow contraction of X' nodes. Would need a way to delete one of the anchor verbs.
Contraction of DP, V', & V Joe eats cookies and ice cream. Allowing contraction of X' won’t help: Neither VP1 nor VP2 fully dominate anything. And remains unordered.
Coordinated Objects Joe eats cookies and ice cream.
When Linearization Chooses Coordinated Subjects –Conjoined DPs, no node contraction –If Conjoined TPs, then requires X' contraction Coordinated Objects –Conjoined DPs, no node contraction –Even with X' contraction, NOT Conjoined TPs
Gapping Sam likes beans and Joe ___ rice. Linearization *Sam ___ beans and Joe likes rice. *Gapping & RNR *Sam likes ___ and Joe ___ rice. *Gapping & ATB movement *What does Sam like ___ and Joe ___ ___?
A pro-Verb Story for Gapping pro-V is the lexical anchor for an elementary tree
A pro-Verb Story for Gapping Like its anchor, the pro-V tree is defective –Cannot have contraction nodes *Gapping & RNR, *Gapping & ATB movement –Depends on a bona fide verb for its interpretation (in some as yet unspecified structural relation) Linearization, Restriction to coordination
Coordinated TPs and the CSC Joe eats cookies and Sam drinks tea.
Coordinated TPs and the CSC *Who eats cookies and Sam drinks tea? What rules out this derivation?
Coordinated TPs and the CSC *What (does) Joe eats cookies and? What rules out this derivation?
Concluding Remarks Linearization... –Requires a means to suppress conflicting information –Requires computation on the global structure –May choose between alternate analyses Gapping is postulated to... –Involve a pro-V and an anaphoric dependency CSC for coordinated TPs... ???
Acknowledgements Bob Frank is gratefully acknowledged for his encouragement and guidance. Thanks also to the Hopkins LingLab and Paul Smolensky for helpful feedback. This work is supported by an NSF IGERT grant.
Relating Coordination and Movement A parallel between elements that can be extracted and elements that can be coordinated (Dowty 1988).
Gapping Tight match between antecedent and gap (cf) ellipsis. –* identifying an active and passive VP Ellipsis:Botanist: That can all be explained. Mr. Spock: Please do ____. Gapping: *The budget cuts might be defended publicly by the chancellor, and the president might defend publicly her labor policies. (Johnson 2003)
Gapping Tight match between antecedent and gap (cf) ellipsis. –* identifying an active and passive VP –* an antecedent fashioned out of two VPs Ellipsis: Wendy is eager to sail around the world and Bruce is eager to climb Killimanjaro, but neither of them can ____ because money is too tight. Gapping: * Wendy should sail the English Channel and Bruce climb Whitney, and their partners should sail and climb the Pacific or Killminjaro.
Gapping Tight match between antecedent and gap (cf) ellipsis. –* identifying an active and passive VP –* an antecedent fashioned out of two VPs –* an antecedent from inside a DP Ellipsis: ?Sal is a talented forger, but Holly can’t ___ at all. Gapping: *Sal may be a forger of passports and Holly may forge paintings.
Gapping Tight match between antecedent and gap (cf) ellipsis. –* identifying an active and passive VP –* an antecedent fashioned out of two VPs –* an antecedent from inside a DP Restricted to coordination