L F G LFG as a component of other approaches LFG has also been adopted as a component of OT and DOP: ■ OT-LFG: Optimality-theoretic syntax with an LFG base (Bresnan, 2000) ■ LFG-DOP: Data-Oriented Parsing with an LFG base (see http://www.nclt.dcu.ie/lfg-dop/publications.html ) Lexical Functional Grammar – 12 / 80
L F G F-structure What information does functional structure represent? Lexical Functional Grammar – 13 / 80
L F G F-structure What information does functional structure represent? ■ Abstract syntactic relations (familiar from traditional grammar) like subject, object, adjunct Lexical Functional Grammar – 13 / 80
L F G F-structure What information does functional structure represent? ■ Abstract syntactic relations (familiar from traditional grammar) like subject, object, adjunct ■ Locus of subcategorisation Lexical Functional Grammar – 13 / 80
L F G F-structure What information does functional structure represent? ■ Abstract syntactic relations (familiar from traditional grammar) like subject, object, adjunct ■ Locus of subcategorisation ■ Criteria: anaphoric binding patterns, long-distance dependencies, control, honorification, agreement, casemarking, ... Lexical Functional Grammar – 13 / 80
L F G F-structure What information does functional structure represent? ■ Abstract syntactic relations (familiar from traditional grammar) like subject, object, adjunct ■ Locus of subcategorisation ■ Criteria: anaphoric binding patterns, long-distance dependencies, control, honorification, agreement, casemarking, ... ■ F-structure vocabulary is universal across languages Lexical Functional Grammar – 13 / 80
L F G Functional structure pred ‘go � subj � ’ tense past � � pred ‘David’ subj num sg Lexical Functional Grammar – 14 / 80
L F G Functional structure pred ‘go � subj � ’ tense past � � pred ‘David’ subj num sg ■ pred , tense num : attributes Lexical Functional Grammar – 14 / 80
L F G Functional structure pred ‘go � subj � ’ tense past � � pred ‘David’ subj num sg ■ pred , tense num : attributes ■ ‘go � subj � ’ , David , sg : values Lexical Functional Grammar – 14 / 80
L F G Functional structure pred ‘go � subj � ’ tense past � � pred ‘David’ subj num sg ■ pred , tense num : attributes ■ ‘go � subj � ’ , David , sg : values ■ past , sg : symbols (a kind of value) Lexical Functional Grammar – 14 / 80
L F G Functional structure pred ‘go � subj � ’ tense past � � pred ‘David’ subj num sg ■ pred , tense num : attributes ■ ‘go � subj � ’ , David , sg : values ■ past , sg : symbols (a kind of value) ■ ‘boy’ , ‘go � subj � ’ : semantic forms Lexical Functional Grammar – 14 / 80
L F G F-structures pred ‘go � subj � ’ tense past � � pred ‘David’ subj num sg �� �� pred ‘quickly’ adj An f-structure can be the value of an attribute. Attributes with f-structure values are the grammatical functions: subj , obj , obj θ , comp , xcomp , ... Lexical Functional Grammar – 15 / 80
L F G F-structures pred ‘go � subj � ’ tense past � � pred ‘David’ subj num sg �� �� pred ‘quickly’ adj A set of f-structures can also be a value of an attribute. Lexical Functional Grammar – 16 / 80
L F G Sets of f-structures pred ‘go � subj � ’ tense past � � pred ‘David’ subj � � pred ‘George’ �� �� pred ‘quickly’ adj Sets of f-structures represent: ■ adjuncts (there can be more than one adjunct) or Lexical Functional Grammar – 17 / 80
L F G Sets of f-structures pred ‘go � subj � ’ tense past � � pred ‘David’ subj � � pred ‘George’ �� �� pred ‘quickly’ adj Sets of f-structures represent: ■ adjuncts (there can be more than one adjunct) or ■ coordinate structures (there can be more than one conjunct) Lexical Functional Grammar – 17 / 80
L F G Describing F-structures ( f num ) = sg is a functional equation. ( f a ) = v holds if and only if f is an f-structure, a is a symbol, and the pair � a, v � ∈ f . A set of formulas describing an f-structure is a functional description. Lexical Functional Grammar – 18 / 80
L F G More Complex Descriptions ( f subj num ) = ( g num ) = sg pred ‘go � subj � ’ � � f pred ‘David’ subj g num sg Lexical Functional Grammar – 19 / 80
L F G Finding the Right F-structure Hindi verbs show person, number, and gender agreement: ( g pred ) = ‘Ram’ Ram ( g case ) = nom ( g pers ) = 3 ( g num ) = sg ( g gend ) = masc Ram calegaa Ram go. future calegaa ( f pred ) = ‘go � subj � ’ ‘Ram will go.’ ( f subj case ) = nom ( f subj pers ) = 3 ( f subj num ) = sg ( f subj gend ) = masc ( f subj ) = g Lexical Functional Grammar – 20 / 80
L F G F-description and its solution ( g pred ) = ‘Ram’ pred ‘go � subj � ’ ( g case ) = nom pred ‘Ram’ ( g pers ) = 3 case nom ( g num ) = sg f subj g pers 3 ( g gend ) = masc num sg ( f pred ) = ‘go � subj � ’ gend masc ( f subj ) = g ( f subj case ) = ( g case ) = nom ( f subj num ) = ( g num ) = sg ( f subj pers ) = ( g pers ) = 3 ( f subj gend ) = ( g gend ) = masc Lexical Functional Grammar – 21 / 80
L F G Formal descriptions: LFG vs HPSG ■ HPSG takes a different view of formal descriptions from LFG. The HPSG view goes back to Functional Unification Grammar (Kay, 1984), where unification (an operation on structures) was used to combine structures: ■ in HPSG, the constraints look (as much as possible) like the structures. ■ That is why you sometimes see a set of instructions in what looks like a representation – it is actually a constraint or description in the (apparent) form of a structure. Lexical Functional Grammar – 22 / 80
L F G Formal descriptions: LFG vs HPSG HPSG’s Argument Realisation Principle (Sag et al., 2003, 432): SPR A VAL COMPS B ⊖ C SYN word : GAP C ARG-STR A ⊕ B ⊖ : list subtraction ⊕ : list addition Lexical Functional Grammar – 23 / 80
L F G Generalisations and constructions ■ Expressing generalisations over functional descriptions: templates (Dalrymple et al., 2004; Asudeh et al., 2008) Lexical Functional Grammar – 24 / 80
L F G Generalisations and constructions ■ Expressing generalisations over functional descriptions: templates (Dalrymple et al., 2004; Asudeh et al., 2008) ■ Templates are names for bundles of functional equations that characterise a construction. Lexical Functional Grammar – 24 / 80
L F G Generalisations and constructions ■ Expressing generalisations over functional descriptions: templates (Dalrymple et al., 2004; Asudeh et al., 2008) ■ Templates are names for bundles of functional equations that characterise a construction. ■ Templates can be defined in terms of other templates, giving something like the inheritence hierarchy of HPSG (but involving relations among descriptions rather than linguistic objects ). Lexical Functional Grammar – 24 / 80
L F G Generalisations and constructions ■ Expressing generalisations over functional descriptions: templates (Dalrymple et al., 2004; Asudeh et al., 2008) ■ Templates are names for bundles of functional equations that characterise a construction. ■ Templates can be defined in terms of other templates, giving something like the inheritence hierarchy of HPSG (but involving relations among descriptions rather than linguistic objects ). ■ Templates can be associated with words or with units that are bigger than words, and are used to describe constructions in the Construction Grammar sense. Lexical Functional Grammar – 24 / 80
L F G Generalisations and constructions ■ Expressing generalisations over functional descriptions: templates (Dalrymple et al., 2004; Asudeh et al., 2008) ■ Templates are names for bundles of functional equations that characterise a construction. ■ Templates can be defined in terms of other templates, giving something like the inheritence hierarchy of HPSG (but involving relations among descriptions rather than linguistic objects ). ■ Templates can be associated with words or with units that are bigger than words, and are used to describe constructions in the Construction Grammar sense. ■ This is a relatively recent area of exploration in LFG. Lexical Functional Grammar – 24 / 80
L F G Semantic Forms Subcategorisation requirements are imposed at f-structure (not c-structure) – a predicate specifies a set of grammatical functions, and the phrase structure grammar of the language determines where in the tree these functions can appear. Subcategorisation requirements are specified by semantic forms : ( f pred ) = ‘go � subj � ’ Semantic forms have argument lists that list the arguments they require. Lexical Functional Grammar – 25 / 80
L F G Grammatical functions Non-argument topic Discourse function focus Argument Core subj (governable) obj Non-discourse function obj θ Non-core obl θ comp Non-argument adj (unct) (from B¨ orjars & Vincent 2004) Lexical Functional Grammar – 26 / 80
L F G Completeness Completeness requires: All arguments which are listed in the semantic form must be present. ( f pred ) = ‘go � subj � ’ “Go” must have a subj . Lexical Functional Grammar – 27 / 80
L F G Coherence Coherence requires: No arguments which are not listed in the semantic form may be present. ( f pred ) = ‘go � subj � ’ “Go” may not have a obj . Lexical Functional Grammar – 28 / 80
L F G Coherence Coherence requires: No arguments which are not listed in the semantic form may be present. ( f pred ) = ‘go � subj � ’ “Go” may not have a obj . Completeness and coherence are the equivalent (more or less) of the Theta Criterion of GB theory, or the Valence Principle and Root Condition of HPSG. Lexical Functional Grammar – 28 / 80
L F G Semantic Forms and Uniqueness * wati ka parnka-mi karnta man. abs pres run- nonpast woman. abs ‘The man runs the woman.’ (Warlpiri) ( g pred ) = ‘man’ wati ( g pred ) = ‘woman’ karnta Each use of a semantic form is unique. Lexical Functional Grammar – 29 / 80
L F G Conflicting Semantic Forms ( g pred ) = ‘man’ wati ( g pred ) = ‘woman’ karnta Ill-formed f-structure: pred ‘run � subj � ’ tense pres � � pred ‘man’/‘woman’ subj g Lexical Functional Grammar – 30 / 80
L F G Optionality njˆ uchi zi-n´ a-l´ um-a alenje bees subj - past -bite- indicative hunters ‘The bees bit the hunters.’ (Chicheˆ wa) zi-n´ a-l´ um-a alenje subj - past -bite- indicative hunters ‘They bit the hunters.’ (( f subj pred ) = ‘pro’ ) zi-n´ a-l´ um-a: um-a optionally contributes a pred for its subj . zi-n´ a-l´ Lexical Functional Grammar – 31 / 80
L F G Overt subject njˆ uchi zi-n´ a-l´ um-a alenje bees subj - past -bite- indicative hunters ‘The bees bit the hunters.’ pred ‘bite � subj,obj � ’ � � pred ‘bees’ subj nounclass 10 f � � pred ‘hunters’ obj nounclass 2 Lexical Functional Grammar – 32 / 80
L F G No overt subject zi-n´ a-l´ um-a alenje subj - past -bite- indicative hunters ‘They bit the hunters.’ pred ‘bite � subj,obj � ’ � � pred ‘pro’ subj nounclass 10 f � � pred ‘hunters’ obj nounclass 2 Lexical Functional Grammar – 33 / 80
L F G Optionality: Clitics Juan vi´ o a Pedro. Juan saw prep Pedro ‘Juan saw Pedro.’ (Spanish) Juan lo vi´ o. Juan acc . masc . sg . clitic saw ‘Juan saw him.’ Juan lo vi´ o a Pedro. Juan acc . masc . sg . clitic saw prep Pedro ‘Juan saw Pedro.’ Lexical Functional Grammar – 34 / 80
L F G Optionality: Clitics ( f pred ) = ‘Pedro’ Pedro ( f gend ) = masc ( f num ) = sg (( f pred ) = ‘pro’ ) lo ( f gend ) = masc ( f num ) = sg Lexical Functional Grammar – 35 / 80
L F G Optionality: Clitics ( f pred ) = ‘Pedro’ Pedro ( f gend ) = masc ( f num ) = sg (( f pred ) = ‘pro’ ) lo ( f gend ) = masc ( f num ) = sg lo optionally contributes a pred . Lexical Functional Grammar – 35 / 80
L F G Optionality: Clitics Juan lo vi´ o a Pedro. Juan acc . masc . sg . clitic saw prep Pedro ‘Juan saw Pedro.’ Lexical Functional Grammar – 36 / 80
L F G Optionality: Clitics Juan lo vi´ o a Pedro. Juan acc . masc . sg . clitic saw prep Pedro ‘Juan saw Pedro.’ pred ‘see � subj,obj � ’ pred ‘Juan’ subj gend masc num sg pred ‘Pedro’ obj gend masc f num sg Lexical Functional Grammar – 36 / 80
L F G Optionality and clitic doubling Juan lo vi´ o. Juan acc . masc . sg . clitic saw ‘Juan saw him.’ pred ‘see � subj,obj � ’ pred ‘Juan’ subj gend masc num sg pred ‘pro’ obj gend masc f num sg Lexical Functional Grammar – 37 / 80
L F G C-structure and f-structure IP NP I ′ pred ‘greet � subj,obj � ’ N VP � � subj pred ‘David’ David V ′ � � obj pred ‘Chris’ V NP greeted N Chris Lexical Functional Grammar – 38 / 80
L F G Motivating Constituent Structure What information does constituent structure represent? Lexical Functional Grammar – 39 / 80
L F G Motivating Constituent Structure What information does constituent structure represent? ■ Represents hierarchical phrasal groupings Lexical Functional Grammar – 39 / 80
L F G Motivating Constituent Structure What information does constituent structure represent? ■ Represents hierarchical phrasal groupings ■ Criteria depend on surface syntactic properties, not semantic intuitions or facts about abstract functional syntactic structure Lexical Functional Grammar – 39 / 80
L F G Motivating Constituent Structure What information does constituent structure represent? ■ Represents hierarchical phrasal groupings ■ Criteria depend on surface syntactic properties, not semantic intuitions or facts about abstract functional syntactic structure ■ Varies greatly across languages Lexical Functional Grammar – 39 / 80
L F G Constituent Structure ■ Some theories (GB/Principles and Parameters, NOT LFG): Subjects always appear in the specifier of IP. Lexical Functional Grammar – 40 / 80
L F G Constituent Structure ■ Some theories (GB/Principles and Parameters, NOT LFG): Subjects always appear in the specifier of IP. ■ LFG does not assume that subjects are defined in terms of phrase structure position, or that subjects must always appear in a particular position in the tree. Lexical Functional Grammar – 40 / 80
L F G Constituent Structure ■ Some theories (GB/Principles and Parameters, NOT LFG): Subjects always appear in the specifier of IP. ■ LFG does not assume that subjects are defined in terms of phrase structure position, or that subjects must always appear in a particular position in the tree. ■ However, there are structure-function mapping generalisations which state that phrases with particular functions tend to appear in particular phrase structure positions. Lexical Functional Grammar – 40 / 80
L F G Constituent Structure ■ Some theories (GB/Principles and Parameters, NOT LFG): Subjects always appear in the specifier of IP. ■ LFG does not assume that subjects are defined in terms of phrase structure position, or that subjects must always appear in a particular position in the tree. ■ However, there are structure-function mapping generalisations which state that phrases with particular functions tend to appear in particular phrase structure positions. ■ In English, the specifier of IP is associated with the subject function; in other languages, it is associated with TOPIC or FOCUS. More below. Lexical Functional Grammar – 40 / 80
L F G Lexical Integrity Lexical Integrity (Bresnan, 1982): Morphologically complete words are leaves of the c-structure tree, and each leaf corresponds to one and only one c-structure node. Lexical Functional Grammar – 41 / 80
L F G Lexical Integrity Lexical Integrity (Bresnan, 1982): Morphologically complete words are leaves of the c-structure tree, and each leaf corresponds to one and only one c-structure node. pred ‘cause � subj,obj,xcomp � ’ English: cause to run subj [ ] obj [ ] Japanese: hasiraseta pred ‘run � subj � ’ run. caus . past xcomp subj Words in one language can express the same f-structure as phrases in another language: Lexical Integrity holds at c-structure, not f-structure. Lexical Functional Grammar – 41 / 80
L F G Economy of Expression Economy of Expression (Bresnan, 2001): All syntactic phrase structure nodes are optional, and are not used unless required by independent principles (completeness, coherence, semantic expressivity). CP C ′ C IP Is NP I ′ N VP David V yawning Lexical Functional Grammar – 42 / 80
L F G CP NP C ′ N IP kogda I ′ when I VP rodilsja NP born N Lermontov Lermontov ‘When was Lermontov born?’ Lexical Functional Grammar – 43 / 80
L F G C-structure and f-structure IP NP I ′ pred ‘greet � subj,obj � ’ N VP � � subj pred ‘David’ David V ′ � � obj pred ‘Chris’ V NP greeted N Chris Lexical Functional Grammar – 44 / 80
L F G C- and F-Structure � � φ V pred ‘greet � subj,obj � ’ tense past greeted φ function relates c-structure nodes to f-structures. (Function: Every c-structure node corresponds to exactly one f-structure.) Lexical Functional Grammar – 45 / 80
L F G Many Corresponding Nodes VP φ � � V ′ pred ‘greet � subj, obj � ’ tense past V greeted Many c-structure nodes can correspond to the same f-structure. Lexical Functional Grammar – 46 / 80
L F G No Corresponding Node S φ pred ‘break � subj � ’ V tense past � � subj pred ‘pro’ kowareta break. past Some f-structures have no corresponding c-structure node. Lexical Functional Grammar – 47 / 80
L F G No Corresponding Node S φ pred ‘break � subj � ’ V tense past � � subj pred ‘pro’ kowareta break. past Some f-structures have no corresponding c-structure node. These are formal, mathematical facts about the c-structure/f-structure relation. What are the linguistic facts? Lexical Functional Grammar – 47 / 80
L F G Mapping regularities C-structure heads are f-structure heads: VP φ � � V ′ pred ‘greet � subj, obj � ’ tense past V greeted Lexical Functional Grammar – 48 / 80
L F G Mapping Regularities Specifiers are filled by grammaticized discourse functions SUBJ, TOPIC, FOCUS. Lexical Functional Grammar – 49 / 80
L F G Mapping Regularities Specifiers are filled by grammaticized discourse functions SUBJ, TOPIC, FOCUS. Specifier of IP in English: SUBJ IP NP I ′ pred ‘yawn � subj � ’ � � N VP subj pred ‘David’ David V yawned Lexical Functional Grammar – 49 / 80
L F G Mapping regularities Specifier of IP in Russian: Topic or Focus IP NP I ′ pred ‘write � subj,obj � ’ �� �� I VP ‘Eugene Evgenija Onegina pred topic Onegin’ Eugene Onegin napisal NP � � subj pred ‘Pushkin’ wrote N obj Puˇ skin Pushkin Lexical Functional Grammar – 50 / 80
L F G Mapping regularities Specifier of IP in Bulgarian: Focus; Specifier of CP: Topic CP pred ‘do � subj,obj � ’ NP C ′ � � topic pred ‘Ivan’ N IP subj Ivan NP I ′ � � Ivan focus pred ‘what’ N I obj kakvo pravi what does Lexical Functional Grammar – 51 / 80
L F G Mapping regularities Specifier of CP in English: Focus CP NP C ′ pred ‘eat � subj,obj � ’ � � N C IP focus pred ‘what’ � � What is NP I ′ subj pred ‘David’ N VP obj David V eating Lexical Functional Grammar – 52 / 80
L F G Mapping regularities Specifier of CP in Finnish: Focus CP NP C ′ pred ‘get � subj,obj,obl source � ’ � � N IP focus pred ‘Mikko’ Mikolta NP I ′ obl source Mikko. abl � � N I VP topic pred ‘Anna’ Anna sai NP subj Anna got � � N obj pred ‘flowers’ kukkia flowers. part Lexical Functional Grammar – 53 / 80
L F G Complements: Functional Categories Complement of functional category is f-structure co-head: pred ‘yawn � subj � ’ � � IP subj pred ‘David’ NP I ′ N I VP David is V yawning Lexical Functional Grammar – 54 / 80
L F G Complements: Functional Categories IP pred ‘read � subj,obj � ’ NP I ′ tense future �� �� N I VP topic pred ‘Anna’ Anna budet V ′ subj � � Anna future obj pred ‘book’ V NP N ˇ citat’ read. inf knigu book Lexical Functional Grammar – 55 / 80
L F G Complements of Lexical Categories Complement of lexical category is f-structure complement (non-subject argument): IP pred ‘greet � subj,obj � ’ � � NP I ′ subj pred ‘David’ � � N VP obj pred ‘Chris’ David V ′ V NP greeted N Chris Lexical Functional Grammar – 56 / 80
L F G Complements of Lexical Categories IP pred ‘give � subj,obj,obj theme � ’ � � NP I ′ subj pred ‘David’ N VP � � obj pred ‘Chris’ David V ′ � � spec pred ‘a’ V NP NP obj theme pred ‘book’ gave N Det N ′ Chris a N book Lexical Functional Grammar – 57 / 80
Constraining the c-structure/f-structure L F G correspondence φ V ′ � � pred ‘yawn � subj � ’ V tense past yawned Lexical Functional Grammar – 58 / 80
Constraining the c-structure/f-structure L F G correspondence φ V ′ � � pred ‘yawn � subj � ’ V tense past yawned − → V V ′ Lexical Functional Grammar – 58 / 80
L F G Local F-Structure Reference φ V ′ � � pred ‘yawn � subj � ’ V tense past yawned − → V V ′ the current c-structure node (“self”): ∗ the immediately dominating node (“mother”): � ∗ the c-structure to f-structure function: φ Lexical Functional Grammar – 59 / 80
L F G Rule Annotation φ V ′ � � pred ‘yawn � subj � ’ V tense past yawned Lexical Functional Grammar – 60 / 80
L F G Rule Annotation φ V ′ � � pred ‘yawn � subj � ’ V tense past yawned − → V ′ V φ ( � ∗ ) = φ ( ∗ ) mother’s ( V ′ ’s) f-structure = self’s ( V’s ) f-structure Lexical Functional Grammar – 60 / 80
L F G Simplifying the Notation φ ( � ∗ ) (mother’s f-structure) = ↑ φ ( ∗ ) (self’s f-structure) = ↓ φ V ′ � � pred ‘yawn � subj � ’ V tense past yawned Lexical Functional Grammar – 61 / 80
L F G Simplifying the Notation φ ( � ∗ ) (mother’s f-structure) = ↑ φ ( ∗ ) (self’s f-structure) = ↓ φ V ′ � � pred ‘yawn � subj � ’ V tense past yawned − → V ′ V ↑ = ↓ mother’s f-structure = self’s f-structure Lexical Functional Grammar – 61 / 80
L F G Using the Notation − → V ′ V ↑ = ↓ mother’s f-structure = self’s f-structure Lexical Functional Grammar – 62 / 80
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