Thematic Roles: The Interface Between Semantics And Syntax

Thematic roles (θ-roles) are semantic roles, which refer to the participant roles in the events or states that predicates describe. The earliest source ofθ-roles can be traced back to kārakas (semantic roles) proposed by the world-famous linguist Pānini in about the 4-6th century B.C.. But it was Gruber who made a systematic research into thematic relations, which are in accordance with semantic deep cases of Fillmore'Case Grammar (1968), and Jackendoff (1972) termed them semantic categories. Years later Chomsky introducedθ-roles into GB theory to reveal the semantic basis of syntactic structures and classified inθ-role the arguments of predicates of natural language to form a group of closed types of participants, which had specific locations in the syntax. Conventionally,θ-roles refer to agent, patient, theme, experiencer, beneficiary, instrument, locations, goal, source, etc.We could not conduct any research intoθ-roles without any concern with arguments that are actually the carriers ofθ-roles, and the close relation between the two is manifested inθ-criterion which requires each argument to bear one and only oneθ-role, and eachθ-role to be assigned to one and only one argument (Chomsky1981:36). Generallyθ-roles and thematic relations are confusing and used interchangeably, and it is Carnie (2002) that made a clear distinction between the two:θ-role is a set of thematic relations of which the most prominent one indicates theθ-role.Considering the discreteness and the uncertainty in number of conventional thematic roles give rise to much inconvenience in the mapping between thematic roles and syntactic arguments, Dowty (1991) proposed Thematic Proto-Roles (i.e. Proto-Agent and Proto-Patient), which are similar to Abstract Semantic Macroroles: Actor and Undergoer suggested by Van Valin Jr. & Lappola (1997).Yet in the current research intoθ-roles still exist some problems, which are respectively the differences in the delicacy of the distinctions ofθ-roles, uncertainty in number, and non-uniformity in terminology; what's more, there is still much necessity in definingθ-roles of some verbs (as resemble, lack, etc.) and the verbs involving weather (as rain, wind, snow, etc.), hence the exploration made into theθ-roles of such verbs in this dissertation.The author of this dissertation holds the belief thatθ-roles are characteristic of meta-language and can be employed for the description of lexical semantics. However, theθ-grid of a verb is changeable in alternation between transitive verbs and intransitive verbs with meaning unchanged. There is a clear cut between transitive verbs and intransitive verbs in traditional grammar following transitivity and intransitivity, namely, transitive verbs with objects and intransitive verbs without any objects. But it is not the case in natural language. With the evolution of language, both transitive verbs and intransitive verbs are changeable, which indicates transitivity is relative to intransitivity and vice versa, and there exists a continuum between them. The change ofθ-grid includes augmentation and minification. The change ofθ-grid results in external and internal motivations: the external one is the language user's pursuit of the simplicity under the economic principles of language, and the internal one is the interaction between verbs and nouns, which makes transitive verbs intransitive because of verbs'absorption of the meaning of nouns, hence the minification ofθ-grid. Another internal motivation, relating to abnormal collocation, say, intransitive verbs with objects leads to the augmentation ofθ-grid.With regard to mapping issues, from the research into lexical relations and semantic cases respectively made by Gruber(1965)and Fillmore(1968),it is found that there exists a correspondence between lexical semantic roles and syntactic locations, therefore number of explorations from different researchers are made into the linking mechanism and the constraints on linking between them, i.e. the mapping theories. Mapping theory is essentially a grammar theory on the corresponding relationship between semantics and syntax. Mappings between semantics and syntax fall into two categories in this dissertation: unmarked mapping and marked mapping. Unmarked mappings refer to general, common, and conventional mapping which follows equivalence class preservation constraints, prominence preservation constraints, absolute mapping algorithm and relative mapping algorithm. On the one hand, unmarked mappings lay much stress on the normal correspondence betweenθ-roles and syntactic arguments; on the other hand, it requires the prominence relations amongθ-roles in the thematic hierarchy to be manifested in syntax. For instance, agent is usually realized as subject, patient/theme realized as object, goal/location as indirect object, and instrument/source as oblique. Marked mappings refers to the unusual, special and abnormal mappings, which are deviated ones occurring in the mapping ofθ-roles and syntactic arguments under rhetorical innovation motivation. In this research, analysis and explorations are made into unmarked mappings including argument-absent mapping, inversed mapping, and asymmetric mapping in construction. Furthermore, the author proposed Suffer-Lose construction.Although many linguists have conducted research into the mapping between semantics and syntax from different perspectives and established different mapping theories and mapping models, each has still something to be desired. Based on the analysis of the defectives of such mapping theories (mapping based on thematic hierarchy, mapping based on thematic proto-roles, mapping based on semantic decomposition, lexical mapping theory, and Wechsler's mapping model), this research has established Integrated Mapping Model which exerts its mapping operations under four driven mechanisms (thematic-driven mechanism, aspectual-driven mechanism, iconicity-driven mechanism, and rhetorical-innovation-driven mechanism).Integrated Mapping Model gives top priority to semantics level. The mapping from semantics to argument structure is subject to thematic driven-mechanism and aspectual driven-mechanism. Thematic driven-mechanism decomposes semantics into different participant roles in the events or activities described by verbs, namely, thematic roles, which are ordered into a thematic hierarchy. Aspectual driven-mechanism decomposes semantics into the aspectual roles measuring an event, such as MEASURE, PATH and TERMINUS, measuring the event from its temporal attributes (duration, recurrence), which are ordered into an aspectual hierarchy. Secondly, the mapping from both thematic roles in thematic hierarchy and aspectual roles in aspectual hierarchy onto arguments in the argument structure is subject to the feature constraint (feature constraint refers to number feature constraint, semantic-function feature constraint, prominence feature constraint and measure feature constraint imposed by both thematic roles and aspectual roles on arguments.).Then the mapping from arguments onto grammatical roles follows two directions (grammatical roles are conventionally ordered into the hierarchy: subject > direct object > indirect object > oblique): one is that arguments are mapped onto the corresponding grammatical roles under the iconicity driven-mechanism (iconicity driven-mechanism requires the arguments in the argument structure (Arguments have already been assigned the features from both thematic and aspectual roles under the feature constraint.) to have iconicity in feature (number feature, semantic function feature, prominence feature and measure feature) with the grammatical roles) realized as unmarked syntactic structure; the other is that arguments are mapped onto the corresponding grammatical roles under rhetorical innovation driven-mechanism (Rhetorical innovation driven-mechanism usually leads to unusual mapping deviated from the normal mapping, which is aroused by language users in pursuit of rhetorical innovation and interference in normal syntactic representation of semantics.) realized as marked syntactic structure. Integrated Mapping Model is as follows:In a word, in this research, except the analysis and comment ofθ-role theory, some supplementation ofθ-role theory is also made. Based on summarizing the current mapping theories, Integrated Mapping Model is established. The findings in the research are conducive to language learner in mastery of lexical semantics, argument structure and the interface between semantics and syntax. On the other hand, it is helpful to the computer-assisted processing of natural language.