The Degree of Dependence in Complex Sentences in Relation to the Scope of Modality in Main Clause

This paper clarifies the degree of dependence between main and subordinate clause in complex sentences that have some types of conjunctive phrases between the two clauses, and describes the elements which determine the degree. Twenty-four types of complex sentences similar to those in Minami (1974) were examined. The scope of modality in main clause was chosen as a criterion for the degree of dependence. Following this criterion, the structures of the complex sentences were categorised as α-structures and β-structures. In the α-structure, the modality of the main clause has scope not only over the propositon of the main clause but over that of the subordinate clause. In the β-structure, the modality of the main clause has scope only over the propositon of the main clause. The degree of dependence is high in α-structurse, whereas it is low in β-structures. Based on these structures, complex sentences are classified into three groups. The judgement of the degree were basically in accord with Minami (1974)'s research. However, my research shows that the semantic and functional relationships between the clauses are important in determining the degree. The semantic relations between the clauses are (1) temporal order and (2) logical sequence. The functional relations are in terms of whether the subordinate clause (1) behaves like adverbial caluse, (2) retains its status of clause, or (3) functions as a modality. This research also shows that as far as semantic and functional relations are different, the degree is different even if the sentences share the same conjunctive phrase morphologically.