- Volume 4 Issue 2
This paper presents a new approach to describing the meanings of English relative clauses with the theoretical framework of Conceptual Structure Theory (henceforth CST)which builds on the pionerring work of Sowa.And this paper aims at proposing some extensions to his work. CST describes the conceptual structrures of sentences with conceptual graphs(henceforth CG). which have begun to be used as an intermediate language in natural language processing and machine translation of computer.CGs are composed of concept types and conceptual relation types. They are a system of logic for semantic representation of sentences. This paper focuses on showing the differences of the CGs according to the functions of English relative clauses. English relative clauses are divided into restrictive and nonrestrictive uses.And this paper describes a restrictive clause with a CG including a expression.which derives from the viewpoint of Montague-semantics and Nom-S Analysis.This paper deals mainly with the relative clauses of double restroction as an example of restrictive relative clauses.The description of a nonrestrictive relative clause does not need any-expression, for it doesn's involve the meaning of set.And this paper links the CG of an appositive relative clause,which is a kind of nonrestrictive clauses,to the concept of the antecedent in the main clause.The description of a nonrestrictive relative clause with adverbial meaning is strated with two CGs for the main clause and the relative clause.They are linked with an appropriate intersentential conceptual relation type according to the contextual realtions between them.This paper also presents a CG of a sentential relative clause,which gives a comment on the main clause.