A Study On The Meaning Construction Of Expositions In New Senior English Textbooks

According to the New National English Curriculum Standard,reading ability is a vital component of language competence and it is essential for students of senior high school to master the unique stylistic structure of expositions.Recently,plenty of studies have focused a lot on the word,grammar and structure of expositions in English textbooks.However,meaning making of expositions at these three levels altogether is seldom focused.Given the context,45 expositions in new senior English textbook(PEP)are selected as research data.Based on the power trio put forward by Martin(2013),this study explores the similarities and differences of meaning construction in general-specific,problem-solving and time-order types of expositions.The UAM corpus tool is used as research tool and semantic wave theory is employed to visualize the movement of meanings in expositions.The major findings are presented as follows:First,from the dimension of power word,the semantic density value of all expositions fluctuates on high levels because of high proportion of technical word and consolidated words.The general semantic profiles of expositions all present downward trends for further explanation.As for the differences,in the time-order type,the proportion of technical word is larger than everyday word,which is strongly related to the repetition of theme words.In the general-specific and the problem-solving types,the technical words are less than everyday words,and the semantic flatlines show regular decreasing trend because core topics are always divided into sub-topics to be explained.Second,from the dimension of power grammar,nominalization is widely employed in expositions.It is found that nominalization of process occupies the highest percentage,followed by nominalization of quality,while other three types of nominalization are less used.As for differences: nominalization of process is more frequently used in problem-solving type,in which many actions and measures existed,so it can achieve concise and accurate texts by shifting verbs into nouns;nominalization of quality takes the larger proportion in time-order type because it contains many adjectives,and it can avoid evaluation and achieve objective texts by changing adjectives to nouns.Third,from the dimension of power composition: as for wave patterns at the lower level(thematic pattern on clause),the constant thematic pattern is the most frequent pattern,followed by linear thematic pattern,while other three patterns are less used;as for wave patterns at the higher level(thematic pattern on hypertheme/macrotheme),the distribution of five patterns shows great differences.In problem-solving type,thematic patterns are adopted and distributed in a relatively balanced way.In the general-specific type,derived pattern is used most frequently because classification and examplification are usually employed to organize text from general concept to specific meaning.In the time-order type,constant thematic pattern takes the largest proportion,which makes it possible to introduce topic in a coherent and in-depth way.This study reveals the meaning-making of three types of expositions in senior English textbooks based on Power Trio put by Martin.This helps English teachers provide guidance of reading and writing of expositions in terms of wording,grammar and structure,so as to improve student’s reading and writing skills of expositions.