抄録
Acquisition of basic adjectives (adjectives that Japanese learners learn at a beginner’s level) by the Japanese learners at an intermediate or advanced level is insufficient. The background is a wide range of use due to the ambiguity of basic adjectives and difficulty of proper use of their synonyms. However, few dictionaries explain how to properly use their synonyms. Also, research on their synonyms has not been sufficiently conducted. Here I analyze both corpuses of the Japanese learner and native Japanese speaker for the synonymous relationship, revealing that 7 basic adjectives meaning "small" and 10 basic adjectives meaning "big" are synonymous.