A Diachronic Study Of Semantic Complexity In American Government Record Texts From A Perspective Of Grammatical Metaphors

Semantic complexity,a manifestation of linguistic complexity characterized by ideational grammar metaphors(Ryshina-Pankova,2015),reflects both language development and communicative appropriateness,and is realized by metaphorical construal of meanings through lexicogrammar choices(Halliday & Matthiessen,2004).With a self-compiled American government-record corpus,this study makes a diachronic study on the semantic complexity of American government record discourse from the perspective of grammatical metaphor,and analyzes how clausal metaphors influence semantic complexity in terms of meta-functions.The self-compiled corpus embodies 80 American government records of different years(1960,1980,2000 and 2020),which are randomly sampled from U.S.Congressional Records posted on its official website(www.congress.gov).Two questions are addressed in this study:1.What are the text-level and the causal-sentence-level trends of semantic complexity in American government record texts?2.How do clausal metaphors influence semantic complexity in terms of meta-functions?First,the corpus is automatically part-of-speech annotated and parsed with Lancs Box 3.0;second,the congruent and metaphorical forms of the causal sentence are retrieved and collected to establish a new clausal metaphor corpus by searching logical items chosen from Roget’s Thesaurus of English Words and Phrases,The Oxford Study Thesaurus,etc.;third,with UAM corpus tool 3.0,the newly built corpus are manually annotated and analyzed in terms of frequencies of logical items metaphors,clausal metaphor types and nominalized forms.The major findings are as follows:(1)At the text level,the semantic complexity of American government record texts generally declines,and in the meantime,follows a specific trend: a significant decrease from 1960 to 1980 and from 2000 to 2020;no significant change from 1980 to 2000.(2)At the causal sentence level,semantic complexity of American government record texts generally declines and is correlated with the year.However,semantic complexity in causal sentences does not change significantly,nor does it follow the specific trend of semantic complexity in the text.(3)Grammatical metaphors in American government record texts contribute to the decline of semantic complexity in two aspects: First,the grammatical metaphors reduction contributes to the semantic complexity decline in both words and sentences.Redundant semantics reduction and missing semantics restoration cause semantic complexity decline in words,and the reduction of transitivity process shift and restoration of the necessary transitivity process cause semantic complexity decline in sentences;Second,the grammatical metaphors reduction contributes to the text style change,which makes the contents more concise and clearer and the information more convenient for readers to refer to.Grammatical metaphors influence semantic complexity more obviously in terms of ideational meta-function than in terms of textual meta-function.