| The English let-construction in this study refers to the imperative constructions introduced by let.This construction is a complex linguistic phenomenon in modern English.Because of its uniqueness and metastab ility in semantics and syntax,this construction has been marginalized in imperative studies,with very few special investigations conducted systematically.The main focus of the literature concerning this construction is about its syntax(such as its Subject and the part of speech of let,etc.),and with very limited research on its semantics.Among the semantic and syntactic descriptions of the construction in the literature,very few scholars are based on large-scale analysis of the authentic corpus data to support their theoretical claims.All these suggest that much work remains to be done in exploring the semantics and syntax of let-construction.Based on the authentic data from the Corpus of Contemporary American English(COCA),the study investigates the TRAN SITIVITY system,MOOD system and functional syntax of let-construction within the theoretical framework of Cardiff Grammar—a model of Systemic Functional Linguistics(SFL),and aims to reveal the semantic and syntactic nature of the construction in real use.With systematic and comprehensive investigation of the const ruction,the study would make contributions to the development of SFL which claims to be a general and appliable linguistic theory,and provide theoretical reference to other linguistic theories on the study of this construction.The research approach carried out in this study is a combination of qualitative and quantitative methods,which aims to solve the following three aspects of questions concerning let-construction.First,what are the Process types and Participant Role configurations of let-construction? How are the semantic features of let-construction distributed in the TRANSITIVITY system?Second,what are the relations between MOOD person and MOOD meaning of let-construction? How are the semantic features of let-construction distributed in the MOOD system?Third,what are the syntactic features of let-construction? How are the meanings of TRANSITIVITY and MOOD realized in syntactic form?After the introduction o f the research background,research significance and research designs,a survey of the literature is to be made with the purpose of bringing out the limitations as well as the contributions of the existing studies and setting the scene for the present stud y.And then the Cardiff Grammar is to be sketched in order to set the theoretical foundations for the present study by focusing on its research paradigms,TRANSITIVITY theory,MOOD theory and functional syntactic theory.Next the TRANSITIVITY system,MOOD system and the functional syntax of let-construction are to be delicately analyzed and described within the theoretical framework of Cardiff Grammar,which aims to bring to light the very nature of the construction in real use,like the patterns of construing experience,assigning communication roles,and the syntactic realizations at the level of form.Finally a conclusion is made.Based on the theoretical framework of Cardiff Grammar,3221 samples of let-construction from COCA have been carefully analyzed and the results have been computed.The main research findings are as follows:First,in terms of TRANSITIVITY,generally the main Process types of let-construction are Action Processes,Mental Processes,Relational Processes and Influential Processes,with very low frequency of Environmental Processes and no Event-relating Processes.In Action Processes,two Participant Roles account for most of the data.In Mental Processes,Cognition Processes have a higher frequency.In Relational Processes,Locational Processes and Directional Processes have a higher frequency.In Influential Processes,covert Agent takes most of the data.T he Process types of let-construction are greatly related to the meaning of let,which may or may not realize Processes in TRANSITIVITY.Within the Process types realized in the construction,Action Processes and Mental Processes are mainly related to the grammaticalized use of let;Influential Processes are mostly related to the lexical verb use of let;and Relational Processes are related to both uses of let stated above.Specifically there are diverse distributions among the Process types realized by different forms of let-construction.Let?s-construction mainly realizes Action Processes,Mental Processes and Relational Processes,with very low frequency of Influential Processes.Let us-construction is very similar to let?s-construction in its Process type distributions with the exception that Influential Processes have a higher frequency,which proves that there are similarities and differences between these two constructions.Let me-construction mainly realizes Mental Processes and Action Processes,and with no great distributional distinctions between Relational Processes and Influential Processes.Among let him/her/them-constructions,Influential Processes take most of the data,while other Process types sharing very low frequencies.In let it-construction,though Influential Processes still account for most of the data,the Relational Processes tend to get a higher frequency,and this construction can also realize Environmental Processes.The Process types realized by Let there-construction are very simple,with Relational Processes taking most of the frequencies.The Influential Processes in let+proper noun-construction still have a higher frequency,but other Process types in this construction are getting a higher frequency than those in let him/her/them/it-constructions.The Participant Role configurations and systemic distributions of TRANSITIVITY are diverse among the different forms of let-construction.The TRANSITIVITY analysis of let-construction in this study shows that this construction has construed very complex human experience,and is a very important lexicogrammatical resource for reflecting reality.Second,as for MOOD,the MOOD person and MOOD meaning of let-construction are greatly constrained by the context of situation and individual‘s discourse purpose.Generally speaking,let-construction mainly realizes [proposal for action] and [formal wish].Dependent on [proposal for action],there are four options: [by self],[by addressee],[by self and addressee] and [by outsider].Under different references of MOOD person,the construction may realize different MOOD meanings with different degrees of imperative force.When the MOOD person refers to [by self and addressee],the construction mainly realizes [firm proposal],[assumption] and [wish].When the MOOD person refers to [by self],it mainly realizes [offer],[suggestion],[self-deliberation] and [wish].When the MOOD person refers to [by addressee],it mainly realizes [command],[request],[suggestion] and [wish].When the MOOD person refers to [by outsider],it mainly realizes [firm proposal] and [wish].Specifically,different forms of let-construction have different systemic distributions in terms of MOOD.There are similarities and differences between let?s-construction and let us-construction.Both of them mainly refer to joint actions carried out by self and addressee,which overwhelmingly realize [firm proposal].Under certain circumstances,they may refer to speaker‘s or addressee(s)‘s actions,which may realize [offer],[suggestion],[request],etc.Let us-construction may also realize [command],referring to the addressee‘s action,while let?s-construction cannot.Let me-construction has a higher degree of grammaticalization,which could have two options in terms of MOOD person: [by self] and [by addressee],with [by self] accounting for most of the data.When the construction refers to the speaker ‘s actions,it mainly realizes [offer] and [suggestion].When the construction refers to the addressee(s)‘s actions,it mainly realizes [request].There are two options among let him/her/them/it-constructions in terms of MOOD person: [by addressee] and [by outsider],with [by addressee] having a higher frequency.When referring to addressee(s)‘s actions,these constructions can realize [command],[request],[suggestion] and [wish],with [suggestion] and [request] having higher frequencies.Whe n referring to the outsider‘s actions,these constructions mainly realize [firm proposal] and [wish],with [firm proposal] having a higher frequency.Let there-construction in modern English is highly conventionalized and formulaic,which overwhelmingly realizes [formal wish].It is only in very special contexts that this construction may refer to addressee(s)‘s actions realizing [request].Let+proper noun-construction also has two options in terms of MOOD person: [by addressee] and [by outsider],with [by outsider] accounting most of the data.The construction mainly realizes [firm proposal] when referring to the outsider ‘s actions,while mainly [suggestion] and [request] could be realized when referring to the addressee(s)‘s actions.The flexibility and diversity of MOOD person and MOOD meaning of let-construction in real use have provided interactants with rich lexicogrammatical resources for selecting communication roles and realizing interpersonal meanings.Third,concerning the syntax of let-construction at the level of form,the syntax of the construction has a close connection with the semantic functions of let.Let-construction in fact has two functional structures: one is the ordinary imperative structure introduced by the lexical verb let,in which let functions as the Main Verb and the implicit addressee you functions as the Subject;the other is the special imperative structure,in which let is only a MOOD marker and functions as a direct element of the clause,i.e.Let Element(abbreviated as L),and the nominal group following let serves the function of Subject.SFL claims that the relationship between meaning and form is that of realization.As for the let-construction with ordinary imperative structure,the main syntactic form to realize TRANSITIVITY is:(S)^ M ^C,i.e.covert Subject ^ Main Verb ^ Complement,and the main syntactic form to realize MOOD is:(S)or(S)^ O,i.e.covert Subject or covert Subject ^ Operator.As for the let-construction with special imperative structure,the main syntactic form to realize TRANSITIVITY is: S ^ M ^ C,i.e.Subject ^ Main Verb ^ Complement,and the main syntactic form to realize MOOD is: L ^ S or O ^ L,i.e.Let Element ^ Subject or Operator ^ Let Element.Let there-construction is to some degree special.The main syntactic form to realize TRANSITIVITY is: M ^ C ^(C),i.e.Main Verb ^ Complement ^ covert Complement,and the main syntactic form to realize MOOD is: L ^ S,i.e.Let Element ^ Subject.Based on COCA corpus data,in this study the TRANSITIVITY system and the MOOD system of let-construction have been delicately described,and the syntax of the construction has been comprehensively analyzed within the theoretical framework of Cardiff Grammar.Semantically the study breaks the tradition of previous studies which mainly investigate the semantics of let-construction from the perspective of MOOD.Syntactically the syntax of let-construction has been revisited from the functional perspective.The study reveals that let-construction is an important lexicogrammatical resource for construing human experience and enacting interpersonal relations.The study highlights the basic principles maintained in SFL such as multifunctional,systemic,contextual,lexis as most delicate grammar,and confirms the appliability and operability of the Cardiff Grammar for explicating some specific linguistic phenomena.The study has enriched and developed the semantic theory and syntactic theory for SFL,which may shed light on text-descriptive work,theoretical-generative work and foreign language teaching.In this study,we try to be comprehensive and systematic in the analyses of semantics and syntax of let-construction,and hope to present the very nature of its usage in real contexts.We expect future research in related fields makes more scientific,more comprehensive,and more systematic studies on this construction. |