How do Japanese language learners choose between synonymous grammatical forms according to the situation?-A comparison with native speakers-

本研究的目的在于澄清以下两点：1）日语学习者如何根据情境选择同义语法形式？2)日语学习者和日语本族语者在根据情境选择同义语法形式方面有什么不同？为了阐明这些观点，本研究考察了表示原因或理由的“kara”和“node”，以及表示传闻的“souda”及其同义词，研究结果如下：1）日语学习者对同义词的显性知识与实际使用之间存在差距。2）日语学习者在选择表达时，会选择与日语语言学和教育领域中视为同义词的表达不同的表达。日语本族语使用者根据情况选择各种不能归纳为词元的同义形式。

The purpose of this research is to clarify the following two points:1) How do Japanese language learners choose between synonymous grammatical forms according to the situation?2) What is the difference between Japanese language learners and Japanese native speakers in choosing between synonymous grammatical forms according to the situation?In order to clarify these points, this research investigated "kara" and "node", used to express cause or reason, and "souda" and its synonymous expressions used to show hearsay.The three results suggested by the research can be stated as follows:1) There is a gap between the Japanese language learners' explicit knowledge and actual usage of synonymous expressions.2) Japanese language learners choose between expressions that differ from the expressions treated as synonymous in the fields of Japanese linguistics and education.3) Japanese native speakers choose according to the situation various synonymous forms that can not be summarized into a lemma.