Introduction to Lexical Functional Grammar Mary Dalrymple, John Lowe, & Louise Mycock Centre for Linguistics and Philology Oxford University Konstanz, November/December 2012 1 / 34 • “Semantic roles, syntactic constituents, and grammatical functions belong to parallel information structures of very different formal character. They are related not by proof-theoretic derivation but by structural correspondences, as a melody is related to the words of a song. The song is decomposable into parallel melodic and linguistic structures, which jointly constrain the nature of the whole. In the same way, the sentences of human language are themselves decomposable into parallel systems of constraints – structural, functional, semantic, and prosodic – which the whole must jointly satisfy.” (Bresnan, 1990) 2 / 34 LFG Two aspects of syntactic structure: • Functional structure is the abstract functional syntactic organisation of the sentence, familiar from traditional grammatical descriptions, representing syntactic predicate-argument structure and functional relations like subject and object. • Constituent structure is the overt, more concrete level of linear and hierarchical organisation of words into phrases. 3 / 34 LFG’s c-structure and f-structure IP NP I′ N VP David V′ V NP greeted N PRED SUBJ OBJ ‘ GREEThSUBJ , OBJi’ h i PRED ‘DAVID ’ h i PRED ‘C HRIS ’ Chris 4 / 34 1 Functional structure PRED TENSE PAST " PRED SUBJ NUM • • • • ‘ GOhSUBJ i’ # ‘DAVID ’ SG PRED , TENSE NUM : attributes ‘ GOhSUBJ i’, DAVID, SG: values PAST , SG : symbols (a kind of value) ‘ BOY ’, ‘ GOhSUBJ i’: semantic forms 5 / 34 F-structures PRED ‘ GO hSUBJ i’ TENSE PAST " # PRED ‘DAVID ’ SUBJ NUM SG nh io PRED ‘ QUICKLY ’ ADJ An f-structure can be the value of an attribute. Attributes with f-structure values are the grammatical functions: SUBJ , OBJ , OBJθ , COMP, XCOMP, ... 6 / 34 F-structures PRED ‘ GOhSUBJ i’ TENSE PAST " # PRED ‘DAVID ’ SUBJ NUM SG nh io PRED ‘ QUICKLY ’ ADJ A set of f-structures can also be a value of an attribute. 7 / 34 Sets of f-structures PRED ‘ GOhSUBJ i’ TENSE PAST h PRED SUBJ h PRED nh ADJ PRED ‘DAVID ’ i ‘G EORGE ’ io ‘ QUICKLY ’ i Sets of f-structures represent: • adjuncts (there can be more than one adjunct) or • coordinate structures (there can be more than one conjunct) 8 / 34 2 C- and F-Structure V φ greeted " PRED TENSE ‘ GREEThSUBJ , OBJ i’ PAST # φ function relates c-structure nodes to f-structures. (Function: Every c-structure node corresponds to exactly one f-structure.) 9 / 34 Constraining the c-structure/f-structure correspondence V′ φ V " PRED TENSE ‘ YAWNhSUBJ i’ PAST # yawned V′ −→ V 10 / 34 Local F-Structure Reference V′ φ V " PRED TENSE ‘ YAWNhSUBJ i’ PAST # yawned V′ −→ V the current c-structure node (“self”): the immediately dominating node (“mother”): the c-structure to f-structure function: ∗ b ∗ φ 11 / 34 Rule Annotation V′ V φ " PRED TENSE ‘ YAWNhSUBJ i’ PAST # yawned V′ −→ V φ(b ∗) = φ(∗) mother’s (V′ ’s) f-structure = self’s (V’s) f-structure 12 / 34 3 Simplifying the Notation φ(b ∗) φ(∗) (mother’s f-structure) (self’s f-structure) φ V′ " V =↑ =↓ ‘ YAWNhSUBJ i’ PRED TENSE PAST # yawned −→ V′ V ↑= ↓ mother’s f-structure = self’s f-structure 13 / 34 Using the Notation −→ V′ V ↑= ↓ mother’s f-structure = self’s f-structure [] V′ V ↑ =↓ 14 / 34 More rules −→ V′ V φ(b ∗) = φ(∗) NP (φ(b ∗) OBJ ) = φ(∗) mother’s f-structure’s OBJ = self’s f-structure In simpler form: −→ V′ V ↑= ↓ NP (↑ OBJ ) =↓ 15 / 34 Using the Notation −→ V′ h ′ V V V ↑= ↓ NP (↑ OBJ OBJ ) [] =↓ i NP 16 / 34 4 Terminal nodes " V yawned ‘ YAWNhSUBJ i’ PRED TENSE PAST # Expressible as: V −→ (↑ yawned = ‘ YAWNhSUBJ i’ (↑ TENSE) = PAST PRED ) Standard form: yawned V (↑ (↑ PRED ) = ‘ YAWNhSUBJ i’ TENSE ) = PAST 17 / 34 Phrase structure rules: English IP −→ NP (↑ I′ SUBJ ) =↓ I VP ↑= ↓ ↑= ↓ −→ I′ ↑= ↓ V ↑= ↓ VP −→ N ↑= ↓ NP −→ 18 / 34 Lexical entries: English yawned V David N (↑ (↑ (↑ PRED ) = ‘ YAWNhSUBJ i’ TENSE ) = PAST PRED ) = ‘DAVID ’ (Standard LFG practice: include only features relevant for analysis under discussion.) 19 / 34 5 Analysis: English IP (↑ fip I′ ↑ fip = ↓fi′ NP SUBJ ) = ↓fnp N ↑ fnp = ↓fn VP ↑ fi′ = ↓fvp David (↑ fn PRED ) = ‘DAVID ’ V ↑ fvp = ↓fv yawned (↑ fv PRED ) = ‘ YAWNhSUBJ i’ (↑ fv TENSE) = PAST 20 / 34 Solving the Description (fip SUBJ ) = fnp fnp = fn (fn PRED ) = ‘DAVID ’ fip = fi′ fi′ = fvp fvp = fv (fv PRED ) = ‘ YAWNhSUBJ i’ (fv TENSE) = PAST fip fi′ fvp fv PRED ‘ YAWNhSUBJ i’ TENSE PAST fnp h SUBJ PRED fn ‘DAVID ’ i 21 / 34 Final result IP NP (fip SUBJ ) = fnp I′ fip = fi′ N fnp = fn VP fi′ = fvp (fn David = ‘DAVID ’ PRED ) (fv PRED ‘ YAWN hSUBJ i’ TENSE PAST h i SUBJ PRED ‘DAVID ’ V fvp = fv yawned = ‘ YAWNhSUBJ i’ (fv TENSE) = PAST PRED ) 22 / 34 6 Semantics in LFG IP NP I′ N′ VP N V′ John V NP married N′ PRED SUBJ OBJ ‘ MARRYhSUBJ , OBJ i’ h i PRED ‘J OHN ’ h i PRED ‘R OSA ’ N Rosa Meaning: marry(john, rosa) How is this meaning composed? 23 / 34 Glue: Composing meanings via deduction Glue (Asudeh, 2004, 2012; Dalrymple, 1999, 2001): Meaning assembly and linear logic • Logic of meanings (semantic level): the level of meanings of utterances and phrases • Logic for composing meanings (‘glue’ level): the level responsible for assembling the meanings of parts to get the meaning of the whole 24 / 34 Meanings Meanings are expressions like David , yawn(David) , yawn ... Function: when applied to an argument, yields a unique value. yawn : applied to David , yields “true”. applied to Fred , yields “true”. applied to George , yields “false”. ... Function application: yawn applied to David = yawn(David) 25 / 34 7 Application and abstraction Lambda abstraction: λX.P represents a function from entities represented by X to entities represented by P . Usually, the expression P contains at least one occurrence of the variable X, and we say that these occurrences are bound by the λ lambda operator. Function application: [λX.P ](a) The function λX.P is applied to the argument a. Equivalent to the expression that results from replacing all occurrences of X in P with a. Example: [λX.yawn (X)](David ) ≡ yawn (David ) 26 / 34 Meaning contributions PRED SUBJ OBJ ‘ MARRYhSUBJ , OBJ i’ h i PRED ‘J OHN ’ h i PRED ‘R OSA ’ • The word John contributes the meaning john. • The word Rosa contributes the meaning rosa. • The word married contributes meaning assembly instructions of the following form: When given a meaning x for my subject and a meaning y for my object, I produce a meaning marry(x, y) for my sentence. 27 / 34 Contribution of ‘John’ NP N′ N john:[ ] h PRED ‘J OHN ’ i John • Every f-structure has a corresponding semantic structure, related to it by the projection function σ (represented by a dotted line). • john:[ ] is a meaning constructor. • In the lexicon: john:↑σ 28 / 34 8 Meaning assembly: Gluing meanings together PRED SUBJ OBJ ‘ MARRYhSUBJ , OBJ i’ [] [] λy .λx.marry(x, y):oσ −◦(sσ −◦mσ ) λy.λx .marry(x, y ): a relation between two individuals x and y that holds if x marries y oσ −◦(sσ −◦mσ ): If I am provided with the semantic structure of my object and then the semantic structure of my subject, I produce the semantic structure of the sentence. In the lexicon: λy .λx.marry(x, y):(↑ OBJ )σ −◦((↑ SUBJ )σ −◦↑σ ) 29 / 34 Proof rules X : fσ P : fσ −◦ gσ P (X) : gσ 30 / 34 Meaning proof for ‘married Rosa’ X : fσ P : fσ −◦ gσ P (X) : gσ rosa:oσ λy.λx.marry(x, y ):oσ −◦(sσ −◦mσ ) λx.marry(x, rosa):sσ −◦mσ 31 / 34 Meaning proof for ‘John married Rosa’ X : fσ P : fσ −◦ gσ P (X) : gσ rosa:oσ λy.λx.marry(x, y ):oσ −◦(sσ −◦mσ ) λx.marry(x, rosa):sσ −◦mσ marry(john, rosa): mσ john:sσ 32 / 34 9 Details are not important for theory of information structure and prosody Our theory of meaning composition, to be explained in the following: rosa:oσ λy.λx.marry(x, y ):oσ −◦(sσ −◦mσ ) λx.marry(x, rosa):sσ −◦mσ marry(john, rosa): mσ john:sσ In fact, however, the details won’t be important for our discussion of information structure. We can use abbreviations like the following, where Rosa stands for any reasonable theory of the meaning of Rosa and how it combines with the rest of the sentence: Rosa married married-Rosa marry(john, rosa): mσ John 33 / 34 Bibliography Asudeh, Ash. 2004. Resumption as Resource Management. Ph.D. thesis, Stanford University. Asudeh, Ash. 2012. The Logic of Pronominal Resumption. Oxford: Oxford University Press. Bresnan, Joan. 1990. Parallel constraint grammar project. CSLI Calendar, 4 October 1990, volume 6:3. Dalrymple, Mary (editor). 1999. Semantics and Syntax in Lexical Functional Grammar: The Resource Logic Approach. Cambridge, MA: The MIT Press. Dalrymple, Mary. 2001. Lexical Functional Grammar , volume 34 of Syntax and Semantics. New York: Academic Press. 34 / 34 10