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LFG Slides based on slides by: Kersti Börjars & Nigel Vincent {k.borjars, n.vincent}@man.ac.uk University of Manchester Winter school in LFG July 4-8 2004 University of Canterbury Christchurch, New Zealand
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Syntactic Formalisms, So Far Goal: Relate surface word order (represented as phrase structure) to predicate-argument structure (close to semantics, represented as dependency structure) TAG: trees combine to form phrase structure, record of derivation is dependency tree HPSG: graphs encode both in intertwined manner LFG: have both trees side by side, and relate them using special functional information
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Types of information about linguistic units Syntactic structure = phrase structure, c-structure the dog forms a constituent in (1) Functional information = dependency, f-structure the dog is the subject in (1) (1) is in past tense Argument structure, a-structure eat takes two arguments Information structure Phonetic structure … (1)The dog ate the rats.
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Correspondence between dimensions (1) The dog ate the rats. (2) The rats were eaten by the dog. subject object deep subject deep object dog rats FunctionDeep syntactic role subject object deep subject deep object dog rats FunctionDeep syntactic role
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Correspondence between dimensions (1) The dog ate the rats. (2) The rats were eaten by the dog. subject object agent theme dog rats FunctionSemantic role subject object agent theme dog rats FunctionSemantic role
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Non-one-to-one correspondence Parallel correspondence approach a-structurec-structure f-structure mapping relations
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a-structure Information relating to the thematic roles associated with a predicate (3)a.tickle b.like Lexical Mapping Theory maps the arguments onto f- structure. Arguments are represented as features.
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f-structure: attributes Types of attributes: Functional features NUM PERS TENSE … Semantic featurePRED Grammatical relations SUBJ OBJ ADJUNCT COMP … A feature value matrix: an unordered set of feature-value pair
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f-structure:values Types of values: Atomic value Value of the functional features: plu, past, 3, fem Semantic formvalue of PRED f-structurevalue of grammatical relations f-structures are reasonably invariant across languages
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f-structure:examples she The goal keeper smiled. Semantic feature Functional features Grammatical relation Functional feature Sw hon Sw Målvakten log. smile past goal keeper sg,def SUBJ
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c-structure Category labelled trees Categories LexicalS, N, V, P, A, (Adv) FunctionalC, I, D Both endocentric (headed) and exocentric (non-headed) structures allowed Cross linguistic variation
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c-structure: functional categories (7)a.The rats will eat the dog. b.Will the rats eat the dog? English: Special status of auxiliary verbs: (9) IP I’ I NP VP will (8)a.The rats ate the dog. b.*Ate the rats the dog?
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c-structure: an interlude (10)The rats ate the dog. Principle of Economy of Expression: all phrase structure nodes are optional unless required by independent principles (completeness, coherence, semantic expressivity) (11) IP I’NP VP the dog V ate NP The rats I VP
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c-structure: “head to head movement” C-structure heads are f-structure heads: XnXn X Complements of functional categories are f-structure co-heads: F’ XP
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Mapping between f-structure and c-structure IP I’ NP VP The dog NPV atethe rats Position: Spec-IP Position: sister of V Case: nominative Case: accusative S NP V rattoscanisdevoravit S NP V canisrattosdevoravit
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Mapping between f-structure and c-structure (12) IP I’ NP VP The NPV ate dog DN therats DN f1f1 f9f9 f8f8 f7f7 f6f6 f5f5 f4f4 f3f3 f2f2 f 10 = I' VP
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Basic lexical entries the dog ate rats
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Mapping between f-structure and c-structure f 10 IP I’ NP VP The NP V ate (12) dog D N therats DN f1f1 f9f9 f8f8 f7f7 f6f6 f5f5 f4f4 f3f3 f2f2 f 1 SUBJ = f 2 f 1 = f 3 f 2 = f 4 f 2 = f 5 f 3 = f 6 f 6 = f 7 f 6 OBJ = f 8 f 8 = f 9 f 8 = f 10 f 4 DEF = + f 5 PRED = ‘dog’ f 5 NUM = sg f 7 PRED = ‘eat ’ f 7 TENSE = past f 9 DEF = + f 10 PRED = ‘rat’ f 10 NUM = pl f 4 PERS = 3 f 9 PERS = 3
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Mapping between f-structure and c-structure f1f1 f2f2 f3f3 f4f4 f5f5 f8f8 f9f9 f 10 f7f7 f6f6 f 7 PRED = ‘eat ’ f 1 SUBJ = f 2 f 1 = f 3 f 2 = f 4 f 2 = f 5 f 3 = f 6 f 6 = f 7 f 6 OBJ = f 8 f 8 = f 9 f 9 = f 10 f 4 DEF = + f 5 PRED = ‘dog’ f 5 NUM = sg f 7 TENSE = past f 9 DEF = + f 10 PRED = ‘rat’ f 10 NUM = pl
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Mapping between f-structure and c-structure f1f1 f2f2 f4f4 f5f5 f8f8 f9f9 f 10 eat past dog sg, def rat pl,def SUBJ OBJ
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Mapping between f-structure and c-structure (12) IP I’ NP VP The NPV ate dog DN therats DN = I' VP eat past dog sg, def rat pl,def SUBJ OBJ
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Well-formedness conditions on f-structure Completeness condition: Coherence condition: (i) all argument functions specified in the value of the PRED feature must be present in the local f-structure, (ii) all arguments so specified must have a PRED value. (i) all argument functions in an f- structure must be specified by their local PRED, (ii) all functions which have a PRED value must be arguments of the element which specifies them. Functional uniqueness: Any attribute has only one value
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Well-formedness conditions on f-structure (14)a.*Oscar tickled. b.*Oscar tickled Sarah the dog’s tummy. c.*The sky rained. Incomplete Incoherent
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Well-formedness conditions on f-structure (14)d.*Tickles her. e.tickles f. Coherent?Yes Complete? No, cf (ii), no PRED value for SUBJ
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Well-formedness conditions on f-structure (14)g.*They tickles her. h.tickles f. Functional uniqueness violated i.they j.
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c-structure: back to Latin (10)a.Canisrattosdevoravit. dog. NOM rat. ACC.PL eat. PERF.3SG b.all orders in possible under right information structural conditions (11) S NP V S V Etc. Morphology builds f-structure: (15)a. b.
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c-structure: back to Latin (15)a. b. (16) S NP V canisrattosdevoravit
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More on functions Grammatical relations SUBJ OBJ ADJUNCT COMP … Semantic featurePRED Functional features NUM PERS TENSE …
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More on functions Non-argument TOP Discourse function FOC Argument Core SUBJ OBJ Non-discourse function OBJ Non- core OBL COMP Non-argument ADJUNCT
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Discourse functions (17)a.Beans, I like.FOCUS b. In Spec-CP c. Incomplete? Complete Functional uncertainty
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COMP function (18)a.Oscar claimed that he liked LFG. b.claim c. VP V CP claimed that he liked LFG
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OBJ and OBL functions Both OBJ and OBL are argument functions which can occur in the PRED feature of a verb. In (19a), a book is OBJ restricted to the role of theme, hence it is an OBJ THEME. A function subscripted with a is restricted to a certain thematic role. In English, an OBL is always a PP, whereas an OBJ is an NP. (19)a.Oscar gave Sarah a book. b.Oscar gave a book to Sarah. The PP to Sarah in (19b), is restricted to having a recipient role, hence it is an OBL RECIP.
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OBJ function (19)The teacher bought Sarah a book. Sarah is OBJa book is OBJ Provide the lexical entry for bought and the other words; Provide the phrase structure rule that is required (remember that it does not have to be binary branching); Add annotations to the phrase structure rule; Draw the tree using the new rule and the ones we have used in the class; Add numbered f-structure variables to each node (f 1, f 2, etc); Write down the equations and solve them to give you the correct f-structure.
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Unbounded Dependency Constructions (1) Who do you think Mary thought John saw - ? The initial element who belongs to 2 clauses simultaneously Different function in each What sort of relation exists between gap and filler? –Constituent - based or f-structure based generalizations –LFG: f-strucutre based generalizations
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F- and c-structure
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Discourse functions (17)a.what did you see? FOCUS b. In Spec-CP FOCUS OBJ DF GF
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Identifying the Function ( focus) = ( obj) ( focus) = ( comp obj) ( focus) = ( comp comp obj) ( focus) = ( comp comp comp obj) ( focus) = ( comp comp comp comp obj) ( focus) = ( subj) ( focus) = ( comp subj) ( focus) = ( comp comp subj) ( focus) = ( comp comp comp subj) ( focus) = ( comp comp comp comp subj)
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Functional Uncertainty
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Reading The main reading for this part comes from: Falk, Yehuda 2001. Lexical-Functional Grammar. An introduction to parallel constraint-based syntax. Stanford, Ca: CSLI Publications. Chapters 1-3 If you want to have some additional reading, try: Bresnan, Joan (2001) Lexical Functional Syntax. Oxford: Blackwell. Chapters 1-4 Dalrymple, Mary (2001) Lexical Functional Grammar. [Syntax and Semantics 34]. New York: Academic Press. Chapters 1-5.
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