Introduction to Lexical Functional Grammar. Wellformedness conditions on f- structures. Constraints on f-structures

Transcription

1 Introduction to Lexical Functional Grammar Session 8 f(unctional)-structure & c-structure/f-structure Mapping II & Wrap-up Summary of last week s lecture LFG-specific grammar rules (i.e. PS-rules annotated with functional schemata) LFG-specific lexicon entries (i.e. annotated with functional schemata) Mapping between f-description (from c-structure) and f-structure Constraints on f- In LFG, a sentence is grammatically correct only if it satisfies 2 criteria The grammar must be able to assign a correct c- structure The grammar must be able to assign a correct wellformed f-structure Moreover the f-structure must match the c- structure and it has to satisfy 3 formal constraints Uniqueness (or Consistency) Condition Coherence Condition Completeness Condition Uniqueness Condition (also called Consistency Condition) Attribute names must be unique and every attribute has a unique value Ex. A clause cannot have two different SUBJs or two different tenses: Inconsistent f-structure SUBJ PRED Veit` SUBJ PRED Tom` PRED TENSE TENSE sleep ( SUBJ) ` PAST FUT Completeness Condition All functions specified in the value of a PRED feature must be present in the local f-structure. Complete f-structure PRED like ( SUBJ) ( OBJ) ` OBJ PRED Mary` Incomplete f-structure PRED like ( SUBJ) ( OBJ) `? Coherence Condition All argument functions in an f-structure must be selected by the local PRED feature. Complete f-structure PRED fall ( SUBJ) ` Incoherent f-structure PRED fall ( SUBJ) `? OBJ PRED Mary` 1

2 Extended Coherence Condition All argument functions in an f-structure must be selected by the local PRED feature. Non-argument functions have to bear an appropriate relation to a PRED: ADJUNCTS must be in f- containing a PRED TOPIC or FOCUS must be identified with, or anaphorically linked to, arguments or adjuncts. Functional equations can be devided into 2 groups Defining equations: The functional equations we have seen so far. They define an f-structure attribute as existing and having a particular value. : do not create a feature-value pair, but require a particular feature value to be present They are notationally distinguished by subscripting the letter c to the equal sign ` = c Ex. bewundern V ( PRED)= bewundern ( SUBJ) ( OBJ) ` ( OBJ CASE)= c ACC The constraining equation does not provide information directly, but constrains (i.e. checks the appropriateness of) information coming from somewhere else The constraining equation will be violated either if the feature is not specified at all somewhere else, or if it is specified differently from what the pronoun (in our example) requires Inequality (negation) It constrains a feature not to have a particular value Represented either ( TENSE) = PRES or ( TENSE) PRES Note: there is no way to interpret the inequality as defining. Therefore, the c subscript is not used in the equations. Existential constraint It requires a feature to be present without requiring that it have a particular value The notation: (f a) Ex. The complementizer that requires its clause to have a finite verb, i.e. a verb with the attribute TENSE. The value of TENSE, however, is irrelevant. Conversely, the complementizer to cannot occur with the feature TENSE: Conditional equations Useful in testing for the presence of a feature as a condition for functional specification Represented by the conditional ` Ex. Malayalam determines the functions of NPs on the basis of their case attributes (K.P. Mohanan, 1982). A nominative case-marked NP can be either a subject or (if inanimated) an object; animate objects are accusative: that to ( TENSE) ( TENSE) a) ( CASE) = NOM ( SUBJ) = b) [( CASE) = ACC & ( ANIM) = +] ( OBJ) = c) [( CASE) = NOM & ( ANIM) = ] ( OBJ) = 2

3 Summary of types of constraining equations a) A = c B positive b) (A = B), A B negative c) (f a) existential d) A B conditional (also defining) Designators like ( SUBJ) ` or ( SUBJ NUM) `areoutside-in: They define a path into the f- structure from a point specified by Inside-out impose a constraint on the larger f-structure. They define, starting at, a path outward past a particular function As notation, the is put at the end Ex. (DF ) Primarily used in the analyses of long-distance dependencies ( wh-movement ) and anaphora Example for inside-out designator What is a wh-word, but in contrast to other wh-words it can only introduce questions in standard English but no relative clauses a) [Who did you see]? the syntactician [who you saw] b) [Where did you read that]? the newspaper [where you read that] c) [What did you eat]? *the falafel [what you ate] Assuming the feature TYPE for clause type with values such as Q, REL, etc. The f-structure in which what appears (DF is some discourse function): TYPE DF Q PRED PRON PRO` WH The lexical item what must lexically specify that the clause in which it occurs has the feature [TYPE Q]: what D ( PRED) = PRO` ((DF ) TYPE = Q ( PRON) = WH Functional uncertainty For example ( SUBJ) or ( SUBJ NUM), etc. represent a fixed path of attributes For some phenomena, e.g. such as anaphora and longdistance dependencies, however, the path cannot be specified in advance. It might be potentially infinite. Functional uncertainty extends functional equations to allow a path of attributes of variable length LFG schemata can contain the metavariables and in addition to and. We will see examples of this in the next sessions f-structure: more examples Expletive pronouns Ex. a) It snows. b) It seems that we are having fun. c) I take it that the world is flat. These are meaningless elements, i.e. they do not refer to a discourse referent, they have no θ-role, but they have a syntactic function Since they are meaningless, they lack the PRED feature; instead they have the FORM feature Since they are non-thematic arguments, they are placed outside the angle brackets 3

4 f-structure: more examples The f-structure for It snows. PRED snow ( SUBJ) ` SUBJ FORM it non-thematic arguments outside the angle brackets no PRED feature, FORM feature instead The most basic grammatical functions are argument functions: SUBJ (subject), OBJ (object), OBJ2 (secondary object), OBL θ (oblique) family POSS (possessor), COMP (complement) The PRED for seem PRED seem < ( COMP) > ( SUBJ) ` There are also non-argument functions: - ADJ (adjunct) - FOCUS, TOPIC Further distinction among argument functions: Core functions: SUBJ, OBJ, OBJ2 Are typically realized as DPs (e.g. English) or nominative and accusative Case (in languages with morphological Case) Are more strictly grammatical functions Non-core functions: OBL θ family Are typically marked with prepositions or Cases expressing θ- roles Are more tied to semantics Argument functions are arranged in a relational hierarchy (Keenan & Comrie 1977) SUBJ > OBJ > OBJ2 > OBL θ (indicates relative accessibility to grammatical processes such as relativization, antecedence of anaphora, etc.) Overlay functions relate a syntactic element to a larger syntactic or discourse structure SUBJ (partially) connects clauses within a sentence TOPIC and FOCUS relate a sentence to the larger discourse (grammaticized) discourse functions (Bresnan 2001) Non-overlay argument functions are also called complement functions argument core noncore SUBJ OBJ OBL θ ADJ OBJ2 COMP POSS overlay nonoverlay nonargument FOCUS TOPIC etc. overlay 4

5 Wrap-up See separate file Wrap-up on our web-site Homework This is a bibliographic work meant as preparation for the sessions in the new year (where you are supposed to write LFG grammar fragments for a particular phenomenon in your (or another) language) Find out until 09 Monday (9 am) which linguistic phenomena in your language seem to be interesting for linguists working in LFG (consult the websites at Stanford and Essex) Write a short summary of no more than half a page (in prose!) and indicate already, if possible, which of the phenomena might interest you 5