The Internal Structure of Copular Sentences with desu and da in Japanese

Abstract

Japanese is a language known for its rich honorific morphology. Different from many Indo-European languages, Japanese language has its honorifics built into the grammar system. Japanese honorifics have many different forms and their usages are not always clearly predictable, which makes it quite challenging for second language learners to grasp. This paper introduces a less-known honorific pattern that clearly shows how Japanese honorifics behave grammatically. The copula verb “be” in Japanese has two forms: a non-honorific form “da” and an honorific form “desu”. “Da” is used under conditions where the speaker indicates an informal or casual talk, while “desu” is used when the speaker intends to present good manners to the listener. From a formal linguistic perspective, a sentence with the plain copula form and one with the honorific copula form have a different underlying structure represented in the grammar of native Japanese speakers. The paper explains such difference between copular sentences with “desu” and “da” by presenting a syntactic structure analysis. It proposes a different internal structure for a copular sentence with “desu” and “da”, and further argues that the sentence with “desu” has “more structure” in the left periphery and presents a different verb position in the internal structure in comparison to the sentence with “da”. The analysis motivates a syntactical way to present and explain the differences in grammatical structures and social contexts of copula use when teaching honorifics in Japanese second language classrooms. It suggests that modern Japanese second language education start teaching honorifics with copular sentences where the distinction between honorific and non-honorific use is very clear and simple.