Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms Principle ideas of LFG (1) Lexical Functional Grammar (Kaplan & Bresnan, 1982): • One level of constituent structure, c-structure, non-transformational. Grammar Formalisms: C-structures are represented with trees. Lexical Functional Grammar (LFG) • A separate level of functional structure, f-structure, representing grammatical functions and predicate-argument Laura Kallmeyer, Timm Lichte, Wolfgang Maier relations. University of T¨ ubingen F-structures are represented with feature structures. Summer term 2007 • Other levels such as argument structure (encoding thematic roles), semantic structure, morphological structure. • Syntactic phenomena (including long-distance dependencies) are treated locally. LFG 1 11 July 2007 LFG 3 11 July 2007 Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms Principle ideas of LFG (2) C-structure F-structure S Overview pred man NP VP subj def + 1. Principle ideas of LFG num sg Det N V NP 2. F-structures tense past the man ate Det N pred ’eat � subj, obj � ’ 3. Linking C-structures and F-structures pred apple the apple 4. Control and raising obj def + num sg 5. Long-distance dependencies 6. Summary LFG 2 11 July 2007 LFG 4 11 July 2007
Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms Principle ideas of LFG (3) F-structures (2) Evidence for a functional representational level comes from Description of f-structures: ( f 1 subj ) = f 2 non-configurational languages. ( f 2 pred ) = ’man’ Example: Warlpiri. ( f 2 def ) = + pred ’man’ (1) The two small children are chasing that dog. subj def + ( f 2 num ) = sg f 2 num sg ( f 1 tense ) = past wita-jarra-rlu ka-pala wajuli-pi-nyi yalumpu kurdu-jarra-rlu maliki tense past ( f 1 pred ) = ’eat � subj, obj � ’ small- pres- chase- npast that. abs child- dog. abs pred ’eat � subj, obj � ’ ( f 1 obj ) = f 3 dual-erg 3du subj dual-erg pred ’apple’ ( f 3 pred ) = ’apple’ obj def + f 1 f 3 ( f 3 def ) = + num sg pred subj obj ( f 3 num ) = sg � agent patient � chase LFG 5 11 July 2007 LFG 7 11 July 2007 Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms F-structures (1) F-structures (3) F-structures are attribute-value structures notated with the usual More examples avm-notation. • ( f 1 subj num ) = sg Linguistic terminology: � �� � f 1 subj num sg • Attributes whose values are f-structues are called grammatical • ( f 1 subj ) = ( f 1 xcomp subj ) functions . subj 1 • Attributes whose values are symbols are called features . � � f 1 xcomp subj 1 • Attributes whose values are semantic forms are called semantic features . LFG 6 11 July 2007 LFG 8 11 July 2007
Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms Linking C-structures and F-structures (1) Linking C-structures and F-structures (3) Each node in the c-structure is linked to exactly one f-structure. The leaves of c-structure trees are words. The f-structures of their pre-terminals come from the lexicon. S pred ’man’ N → man NP VP subj def + ( ↑ pred ) = ’man’, f 2 num sg ( ↑ num ) = sg Det N V NP tense past Det → the the man ate Det N pred ’eat � subj, obj � ’ ( ↑ def ) = + pred ’apple’ the apple obj def + NP → Det N f 1 f 3 With the NP-rule we obtain for the num sg ↑ = ↓ ↑ = ↓ NP the man the f-structure pred ’man’ def + num sg LFG 9 11 July 2007 LFG 11 11 July 2007 Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms Linking C-structures and F-structures (2) Linking C-structures and F-structures (4) C-structures are described with standard phrase structure rules. Further conditions on the final minimal f-structure constructed from the defining equations specify that the predicate-argument S → NP VP, NP → Det N, . . . requirements in the f-structure must be satisfied. The phrase structure rules are equipped with information about how the mother f-structure and the daughter f-structures are • Completeness related. All functions specified in the value of a pred must be present For a given node, the symbols ↑ and ↓ refer to the f-structures of in the local f-structure of that pred . the mother node and of the node itself. • Coherence S → NP VP All argument functions in an f-structure must be selected by ( ↑ subj ) = ↓ ↑ = ↓ the local pred feature. NP → Det N ↑ = ↓ ↑ = ↓ VP → V NP ↑ = ↓ ( ↑ obj ) = ↓ LFG 10 11 July 2007 LFG 12 11 July 2007
Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms Control and raising (1) Control and raising (3) Control: (6) John persuaded Bill to eat the apples. (2) John believes to understand f-structures. � � subj pred ’John’ (3) John promised Bill to eat the apples. tense past pred ’persuade � subj, obj, xcomp � ’ (4) John persuaded Bill to eat the apples. 1 � � obj pred ’Bill’ An argument of the matrix verb is identical to the non-overt subj subject of the complement clause. 1 pred ’eat � subj, obj � ’ There is no empty category PRO; the control relation is xcomp pred ’apple’ represented only in the f-structure. obj def + num sg V → persuaded ( ↑ pred ) = ’persuade � subj, obj, xcomp � ’ ( ↑ obj ) = ( ↑ xcomp subj ) LFG 13 11 July 2007 LFG 15 11 July 2007 Kallmeyer/Lichte/Maier Grammar Formalisms Kallmeyer/Lichte/Maier Grammar Formalisms Control and raising (2) Control and raising (4) Raising: (5) John believes to understand f-structures. 1 � � (7) John seems to eat the apples subj pred ’John’ (8) John believes Bill to like Mary tense pres pred ’believe � subj, xcomp � ’ An athematic argument of the main verb is identical with the subj 1 non-overt subject of the embedded verb. pred ’understand � subj, obj � ’ Athematic arguments are listed in the pred value (to satisfy xcomp pred ’f-structure’ coherence) but occur outside the brackets � . . . � . obj def - num pl V → believes ( ↑ pred ) = ’believe � subj, xcomp � ’ ( ↑ subj ) = ( ↑ xcomp subj ) LFG 14 11 July 2007 LFG 16 11 July 2007
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