List of Figures

• Elementary trees in TAG
• XTAG system diagram
• Output Structures from the Parser
• Interfaces database
• XTAG Interface
• Different subcategorization frames for the verb buy
• Trees illustrating the difference between Complements and Adjuncts
• Lexicalized NP trees with case markings
• Assigning case in prepositional phrases
• Case assignment to NP arguments
• Assigning case according to verb form
• Proper case assignment with auxiliary verbs
• Declarative Intransitive Tree: $\alpha$nx0V
• Declarative Transitive Tree: $\alpha$nx0Vnx1
• Declarative Ditransitive Tree: $\alpha$nx0Vnx1nx2
• Declarative Ditransitive with PP Tree: $\alpha$nx0Vnx1pnx2
• Declarative Ditransitive with PP shift Trees: $\alpha$nx0Vnx1Pnx2 (a) and $\alpha$nx0Vnx2nx1 (b)
• Declarative Sentential Complement with NP Tree: $\beta$nx0Vnx1s2
• Declarative Intransitive Verb Particle Tree: $\alpha$nx0Vpl
• Declarative Transitive Verb Particle Tree: $\alpha$nx0Vplnx1 (a) and $\alpha$nx0Vnx1pl (b)
• Declarative Ditransitive Verb Particle Tree: $\alpha$nx0Vplnx1nx2 (a), $\alpha$nx0Vnx1plnx2 (b) and $\alpha$nx0Vnx1nx2pl (c)
• Declarative Intransitive with PP Tree: $\alpha$nx0Vpnx1
• Declarative PP Complement Tree: $\alpha$nx0VPnx1
• Declarative Sentential Complement Tree: $\beta$nx0Vs1
• Declarative Intransitive with Adjective Tree: $\alpha$nx0Vax1
• Declarative Sentential Subject Tree: $\alpha$s0Vnx1
• Declarative Light Verb Tree: $\alpha$nx0lVN1
• Declarative Light Verbs with PP Tree: $\alpha$nx0lVN1Pnx2 (a), $\alpha$nx0lVnx2N1 (b)
• Declarative NP It-Cleft Tree: $\alpha$ItVpnx1s2
• Declarative PP It-Cleft Tree: $\alpha$ItVnx1s2
• Declarative Adverb It-Cleft Tree: $\alpha$ItVad1s2
• Declarative Adjective Small Clause Tree: $\alpha$nx0Ax1
• Declarative Adjective Small Clause with Sentential Complement Tree: $\alpha$nx0A1s1
• Declarative Adjective Small Clause with Sentential Subject Tree: $\alpha$s0Ax1
• Declarative Equative BE Tree: $\alpha$nx0BEnx1
• Declarative NP Small Clause Trees: $\alpha$nx0N1
• Declarative NP with Sentential Complement Small Clause Tree: $\alpha$nx0N1s1
• Declarative NP Small Clause with Sentential Subject Tree: $\alpha$s0N1
• Declarative PP Small Clause Tree: $\alpha$nx0Pnx1
• Declarative Exhaustive PP Small Clause Tree: $\alpha$nx0Px1
• Declarative PP Small Clause with Sentential Subject Tree: $\alpha$s0Pnx1
• Declarative Intransitive Sentential Subject Tree: $\alpha$s0V
• Sentential Subject Tree with `to' complement: $\alpha$s0Vtonx1
• Declarative PP Small Clause tree with two-word preposition, where the first word is an adverb, and the second word is a preposition: $\alpha$nx0ARBPnx1
• Declarative PP Small Clause tree with two-word preposition, where the first word is an adjective, and the second word is a preposition: $\alpha$nx0APnx1
• Declarative PP Small Clause tree with two-word preposition, where the first word is a noun, and the second word is a preposition: $\alpha$nx0NPnx1
• Declarative PP Small Clause tree with two-word preposition, where both words are prepositions: $\alpha$nx0PPnx1
• Declarative PP Small Clause tree with three-word preposition, where the middle noun is marked for null adjunction: $\alpha$nx0PNaPnx1
• Declarative PP Small Clause with Sentential Subject Tree, with two-word preposition, where the first word is an adverb, and the second word is a preposition: $\alpha$s0ARBPnx1
• Declarative PP Small Clause with Sentential Subject Tree, with two-word preposition, where the first word is an adjective, and the second word is a preposition: $\alpha$s0APnx1
• Declarative PP Small Clause with Sentential Subject Tree, with two-word preposition, where the first word is a noun, and the second word is a preposition: $\alpha$s0NPnx1
• Declarative PP Small Clause with Sentential Subject Tree, with two-word preposition, where both words are prepositions: $\alpha$s0PPnx1
• Declarative PP Small Clause with Sentential Subject Tree, with three-word preposition, where the middle noun is marked for null adjunction: $\alpha$s0PNaPnx1
• Predicative Adjective with Sentential Subject and Complement: $\alpha$s0A1s1
• Declarative Locative Adverbial Small Clause Tree: $\alpha$nx0nx1ARB
• Wh-moved Locative Small Clause Tree: $\alpha$W1nx0nx1ARB
• ECM Tree: $\beta$Xnx0Vs1
• Declarative Transitive Idiom Tree: $\alpha$nx0VDN1
• Declarative Idiom with V, D, A, and N Anchors Tree: $\alpha$nx0VDAN1
• Declarative Idiom with V and N Anchors Tree: $\alpha$nx0VN1
• Declarative Idiom with V, A, and N Anchors Tree: $\alpha$nx0VAN1
• Declarative Idiom with V, D, A, N, and Prep Anchors Tree: $\alpha$nx0VDAN1Pnx2
• Declarative Idiom with V, A, N, and Prep Anchors Tree: $\alpha$nx0VAN1Pnx2
• Declarative Idiom with V, N, and Prep Anchors Tree: $\alpha$nx0VN1Pnx2
• Declarative Idiom with V, D, N, and Prep Anchors Tree: $\alpha$nx0VDN1Pnx2
• Ergative Tree: $\alpha$Enx1V
• Tree $\beta$COMPs, anchored by that
• Sentential complement tree: $\beta$nx0Vs1
• Trees for The emu thinks that the aardvark smells terrible.
• Tree for Who smells terrible?
• ECM tree: $\beta$Xnx0Vs1
• Sample ECM parse
• ECM passive
• Comparison of <assign-comp> values for sentential subjects: $\alpha$s0Vnx1 (a) and sentential complements: $\beta$nx0Vs1 (b)
• Sample trees for preposition: $\beta$Pss (a) and noun: $\alpha$NXNs (b) taking sentential complements
• Tree for persuaded
• Tree for leave
• Derived tree for Srini persuaded Mickey to leave
• Derivation tree for Srini persuaded Mickey to leave
• Predicative trees: $\alpha$nx0N1 (a), $\alpha$nx0Ax1 (b) and $\alpha$nx0Pnx1 (c)
• Copula auxiliary tree: $\beta$Vvx
• Predicative AP tree with features: $\alpha$nx0Ax1
• Consider tree for embedded small clauses
• Raising verb with experiencer tree: $\beta$Vpxvx
• Raising adjective tree: $\beta$Vvx-adj
• Equative BE trees: $\alpha$nx0BEnx1 (a) and $\alpha$Invnx0BEnx1 (b)
• Dative shift trees: $\alpha$nx0Vnx1Pnx2 (a) and $\alpha$nx0Vnx2nx1 (b)
• It-cleft with PP clefted element: $\alpha$ItVpnx1s2 (a) and $\alpha$InvItVpnx1s2 (b)
• Passive trees in the Sentential Complement with NP tree family: $\beta$nx1Vs2 (a), $\beta$nx1Vbynx0s2 (b) and $\beta$nx1Vs2bynx0 (c)
• Transitive tree with object extraction: $\alpha$W1nx0Vnx1
• Intransitive tree with subject extraction: $\alpha$W0nx0V
• Ditransitive trees with direct object: $\alpha$W1nx0Vnx1nx2 (a) and indirect object extraction: $\alpha$W2nx0Vnx1nx2 (b)
• Ditransitive with PP tree with the object of the PP extracted: $\alpha$W2nx0Vnx1pnx2
• Ditransitive with PP with PP extraction tree: $\alpha$pW2nx0Vnx1pnx2
• Predicative Adjective tree with extracted adjective: $\alpha$WA1nx0Vax1
• Relative clause trees in the transitive tree family: $\beta$Nc1nx0Vnx1 (a) and $\beta$N0nx0Vnx1 (b)
• Adjunct relative clause tree with PP-pied-piping in the transitive tree family: $\beta$Npxnx0Vnx1
• Determiner tree with <rel-clause> feature: $\beta$Dnx
• Auxiliary Trees for Subordinating Conjunctions
• Trees Anchored by Subordinating Conjunctions: $\beta$vxPARBPs and $\beta$vxParbPs
• Sample Participial Adjuncts
• Example of discourse conjunction, from Seuss' The Lorax
• Transitive imperative tree: $\alpha$Inx0Vnx1
• Determiner Gerund tree from the transitive tree family: $\alpha$Dnx0Vnx1
• NP Gerund tree from the transitive tree family: $\alpha$Gnx0Vnx1
• Passive Gerund trees from the transitive tree family: $\alpha$Gnx1Vbynx0 (a) and $\alpha$Gnx1V (b)
• NP Tree
• Determiner Trees with Features
• Multi-word Determiner tree: $\beta$DDnx
• Genitive Determiner Tree
• Genitive NP tree for substitution: $\alpha$DnxG
• Partitive Determiner Tree
• (a) Adverb modifying a determiner; (b) Adverb modifying a noun phrase
• Standard Tree for Adjective modifying a Noun: $\beta$An
• Multiple adjectives modifying a noun
• Noun-noun compounding tree: $\beta$Nn (not all features displayed)
• Time Phrase Modifier trees: $\beta$Ns, $\beta$Nvx, $\beta$vxN, $\beta$nxN
• Time NPs with and without a determiner
• Time NP trees: Two different attachments
• Time NPs in different positions ($\beta$vxN, $\beta$nxN and $\beta$Ns)
• Time NPs: Derived tree and Derivation ($\beta$Nvx position)
• Selected Prepositional Phrase Modifier trees: $\beta$Pss, $\beta$nxPnx, $\beta$vxP and $\beta$vxPPnx
• Adverb Trees for pre-modification of S: $\beta$ARBs (a) and post-modification of a VP: $\beta$vxARB (b)
• Derived tree for How did you fall?
• Complex adverb phrase modifier: $\beta$ARBarbs
• Selected Focus and Multi-word Adverb Modifier trees: $\beta$ARBnx, $\beta$PARBd and $\beta$PaPd
• Selected Multi-word Adverb Modifier trees (for adverbs like sort of, kind of): $\beta$NPax, $\beta$NPvx, $\beta$vxNP.
• Selected Multi-word Adverb Modifier trees (for adverbs like a little, a bit): $\beta$vxDA, $\beta$DAax, $\beta$DNpx.
• Locative Modifier Trees: $\beta$nxnxARB, $\beta$nxARB
• Locative Phrases featuring NP and Adverb Degree Specifications
• Auxiliary verb tree for non-inverted sentences: $\beta$Vvx
• Auxiliary trees for The music should have been being played .
• The music should have been being played .
• Trees for auxiliary verb inversion: $\beta$Vs (a) and $\beta$Vvx (b)
• will John buy a backpack ?
• Tree for adjective conjunction: $\beta$a1CONJa2 and a resulting parse tree
• Tree for NP conjunction: $\beta$CONJnx1CONJnx2 and a resulting parse tree
• Tree for determiner conjunction: $\beta$d1CONJd2.ps
• Tree for sentential conjunction: $\beta$s1CONJs2
• $\beta$a1CONJa2 (a) anchored by comma and (b) anchored by and
• Tree for conjunction with but-not: $\beta$px1CONJARBpx2
• Tree for conjunction with not-but: $\beta$ARBnx1CONJnx2
• Example of conjunction with to
• Coordination schema
• An example of the conjoin operation. $\{1\}$ denotes a shared dependency.
• Coordination as adjunction.
• Tree for Metalinguistic Adjective Comparative: $\beta$ARBaPa
• Tree for Adjective-Extreme Comparative: $\beta$ARBPa
• Nominal comparative trees
• Tree for Lone Comparatives: $\alpha$CARB
• Comparative conjunctions.
• Comparative conjunctions.
• Adjunction of $\beta$nxPnx to NP modified by comparative adjective.
• Elliptical adjectival comparative trees
• Comparativized adjective triggering $\beta$CnxPnx.
• Adjunction of $\beta$axPnx to comparative adjective.
• Adverbial comparative trees
• The $\beta$nxPUnxPU tree, anchored by parentheses
• An N-level modifier, using the $\beta$nPUnx tree
• The derived trees for an NP with (a) a peripheral, dash-separated appositive and (b) an NP colon expansion (uttered by the Mouse in Alice's Adventures in Wonderland)
• The $\beta$PUpxPUvx tree, anchored by commas
• Tree illustrating the use of $\beta$PUpxPUvx
• A tree illustrating the use of sPUnx for a colon expansion attached at S.
• $\beta$PUsPU anchored by parentheses, and in a derivation, along with $\beta$PUnxPU
• $\beta$PUs, with features displayed
• $\beta$sPUs, with features displayed
• Metarule for wh-movement of subject
• Metarule for wh-movement of object
• Metarule for general wh movement of an NP
• Application of wh-movement rule to Tnx0Vnx1Pnx2
• Parallel application of metarules
• Sequential application of metarules
• Cumulative application of metarules
• Lexical Organization: System Overview
• Some subcategorization blocks
• Transformation blocks for extraction
• Elementary trees generated from combining blocks
• Partial inheritance lattice in English
• Implementation of the system
• Interface for creating a grammar
• Part of the Interface for creating blocks

Abstract:

This document describes a sizable grammar of English written in the TAG formalism and implemented for use with the XTAG system. This report and the grammar described herein supersedes the TAG grammar described in [#!tech-rept95!#]. The English grammar described in this report is based on the TAG formalism developed in [#!joshi75!#], which has been extended to include lexicalization ([#!schabes88!#]), and unification-based feature structures ([#!vijay91!#]). The range of syntactic phenomena that can be handled is large and includes auxiliaries (including inversion), copula, raising and small clause constructions, topicalization, relative clauses, infinitives, gerunds, passives, adjuncts, it-clefts, wh-clefts, PRO constructions, noun-noun modifications, extraposition, determiner sequences, genitives, negation, noun-verb contractions, sentential adjuncts and imperatives. This technical report corresponds to the XTAG Release 8/31/98. The XTAG grammar is continuously updated with the addition of new analyses and modification of old ones, and an online version of this report can be found at the XTAG web page: http://www.cis.upenn.edu/~xtag/.

Acknowledgements

We are immensely grateful to Aravind Joshi for supporting this project. The following people have contributed to the development of grammars in the project: Anne Abeille, Jason Baldridge, Rajesh Bhatt, Kathleen Bishop, Raman Chandrasekar, Sharon Cote, Beatrice Daille, Christine Doran, Dania Egedi, Tim Farrington, Jason Frank, Caroline Heycock, Beth Ann Hockey, Roumyana Izvorski, Karin Kipper, Daniel Karp, Seth Kulick, Young-Suk Lee, Heather Matayek, Patrick Martin, Megan Moser, Sabine Petillon, Rashmi Prasad, Laura Siegel, Yves Schabes, Victoria Tredinnick and Raffaella Zanuttini. The XTAG system has been developed by: Tilman Becker, Richard Billington, Andrew Chalnick, Dania Egedi, Devtosh Khare, Albert Lee, David Magerman, Alex Mallet, Patrick Paroubek, Rich Pito, Gilles Prigent, Carlos Prolo, XTAG Project, Yves Schabes, William Schuler, B. Srinivas, Fei Xia, Yuji Yoshiie and Martin Zaidel. We would also like to thank Michael Hegarty, Lauri Karttunen, Anthony Kroch, Mitchell Marcus, Martha Palmer, Owen Rambow, Philip Resnik, Beatrice Santorini and Mark Steedman. In addition, Jeff Aaronson, Douglas DeCarlo, Mark-Jason Dominus, Mark Foster, Gaylord Holder, David Magerman, Ken Noble, Steven Shapiro and Ira Winston have provided technical support. Adminstrative support was provided by Susan Deysher, Carolyn Elken, Jodi Kerper, Christine Sandy and Trisha Yannuzzi. This work was partially supported by NSF Grant SBR8920230 and ARO Grant DAAH0404-94-G-0426.