| Subjects and predicates are very special among the numerous phrases. Some scholars call it "the multi-functional phrases". There has been much research about subjects and predicates phrase, mainly at the syntactic level, but little research at the semantic and pragmatic levels. Based on the previous studies, the author adopts the grammar theory as the guiding principle and such methods of semantic theory, analysis of semantic features, semantic co-ordinate valence analysis, information structure, conversational implicature, focal point analysis. This thesis will focus on the features and functions of semantic and pragmatic levels. There are four chapters of this thesis.The first chapter is the introduction which includes literature review of the related research of the subjects and predicates, the significance of the research, research methods and data.The second chapter is the semantic analysis which centers on the semantic relationship of the subjects and predicates phrase and core verb structure relationship, the language mold of subjects and predicates phrase and the analysis of ambiguity.1) to study the common semantic types from the static and dynamic perspectives. The include:agent, send matter, after matter, department matter and stages a rebellion, dynamic increased accomplishment, cause matter and assumes office four kinds; According to the verb semantic features, the predicates may be divided into core verb, cause core, character core, experience core and relational core; 2) to explore the relationship of the subjects and predicates phrase and the skeleton core verb structure from the static and dynamic perspectives. From the static perspective, the subject and predicate phrase is the syntactic representations of skeleton core verb structure, the skeleton core verb structure is the subjects and predicates phrase semantic representations; from the dynamic perspective, a part with the static stratification plane's relations is consistent, but, some core verb structures are implied and inconsistent with the subject and predicate phrases; 3) Based on the above analysis, the 25 kinds of smallest language mold subject and predicate phrases are found according to the co-ordinate valence theory. Their syntactic positions as well as semantic relations between various parts are reflected.4) An analysis of the ambiguity of the smallest units of the subject and predicate phrases above the sentence levels are presented.The third chapter is a pragmatic analysis of the abbreviated explanation in phrases, the pragmatic functions in the subject sentence, relationship in sentence and focal point, the pragmatics function of each kind of syntactic component's language uses.1) Subject and predicate word order change can highlight the recent information, express the different emotional color, for example, stressing the key points of the narration, the special feelings of the storyteller, storyteller's question, storyteller's requests and so on.2) The omission of some subject and predicate phrases can make the language concise and coherent so that the communication goes smoothly.3) The subject and predicate phrase can adjust the information structure and therefore add to the amount of information. The structure becomes "the new information+old information" by "the old information+new information" structure.4) Subject and predicate phrases make the static focal point usually to be located at the sentence end, make the dynamic focal point quite to be nimble, may be consistent with the static focal point, but may not be inconsistent with the static focal point; the static focal point usually acts as the object, the attribute or the adverb, which can be the subject and predicate phrases alone construable situation, but if as the dynamic focal point, there exist clauses of only subjects and predicates phrase.5) Subject and predicate phrases can add to the amount of information when used as the object, the attribute, the adverbial and the complement. When they are used as the object, they can change word order and emphasize the new information and lead to the topic in the following context.The fourth chapter is the conclusion which restate the main points of the thesis. |