A Study Of The Diachronic Change Of Modal Need And Semi-Modal Need To:A Corpus-Based Approach

Grammaticalization is typically a unidirectional change from the diachronic perspective.However,the existence of counterexamples of unidirectionality has also been confirmed by scholars who have studied modal and semi-modal verbs.As for the decrease of the modal verb need and the increase of the semi-modal verb need to over the last century,the changing patterns have not been clearly defined by those scholars.Therefore,under the guidance of grammaticalization theory and critical frequency theory,this thesis quantitatively analyzes the frequency distributions and the diachronic changes of the modal verb need and semi-modal need to since the late Middle English,based on several corpora.The purpose of this study is to address the following three issues:first,to ascertain the diachronic directionality of various forms of the verb need;second,to identify the respective grammaticalization path of the semimodal verb need to and the modal verb need;third,to determine the critical context and critical frequency that lead to the grammaticalization of the modal verb need.This thesis diachronically traces the origin of need.According to the Oxford English Dictionary(OED),the verbal form of need can be divided into the modal verb need,the semimodal verb need to,and the blends.In this thesis,frequency distributions of various forms of the verb need are explored based on five corpora,including EEBO,ARCHER,COHA,COCA and BNC,with a quantitative research method.The aim is to reveal the diachronic changing patterns of the modal need and semi-modal need to since the late 15th century.The study starts from two aspects:regional and stylistic distributions,and diachronic distributions of modal and semi-modal verbs.With regard to dialects and genres,on the one hand,the modal need fluctuates more in American English,while it is more stable in British English.Moreover,American English seems to be leading the development of the semi-modal need to.On the other hand,the modal need is more common in written texts,while the semi-modal need to is more often found in spoken genres.Concerning the diachronic distributions of modal verbs and semimodal verbs,the modal need is found to be consistent with most of the core modal verbs,experiencing an increase and then a decrease in frequency.In contrast,semi-modal need to,whose frequency has soared in the last century,also keeps pace with the maj ority of semi-modal verbs.The reason for this phenomenon is,first of all,that semi-modal verbs are syntactically more flexible and accessible to all contexts.Furthermore,the inequality of power expressed by language is gradually disappearing in a more democratic society.On this basis,the thesis further explores the diachronic directionality of the verb need.By analyzing the relationship of different forms of the verb need,it is found that the development of the modal verb need and the semi-modal verb need to does not belong to degrammaticalization or retraction as suggested by some scholars.Both of them originate from the verb need and are in line with a polygrammaticalization change.With regard to the diachronic change path of semi-modal need to,its basic meaning expresses an "internal compulsion",from which all subsequent meanings originate,including the deontic and dynamic meanings,as well as the developing epistemic meaning.Moreover,the development of semimodal need to from "participant internal modality" to "participant external modality" is in accordance with the "semantic map" proposed by van der Auwera and Plungian(1998).That is to say,semi-modal need to is undergoing a grammaticalizing change.Regarding the grammaticalization of the modal verb need,this thesis is the first attempt to apply critical frequency theory to the grammaticalization study,and identify the critical context and critical frequency of modal need.The result shows that there is more than one critical context leading to the grammaticalization of the modal need.Both structures,"need not be+other elements"and "need not+adverb",have the conditions for pragmatic inference to trigger grammaticalization.The critical frequency serves as its threshold to grammaticalization.The diachronic thickness lasts four centuries(16th century-19 century)and the synchronic intensity accumulates to 14.5 pmw.