The objective of this paper is to analyze approximately 3,000 English vocabulary items that commonly appear in Japanese junior high and high school English textbooks officially approved by the Ministry of Education, Culture, Sports, Science and Technology. Vocabulary items from English textbooks were compared with a same-sized vocabulary list derived from an English speech corpus. A comparative analysis of the two lists shows how (relatively) well the textbook vocabulary represents a group of English words that most frequently appear in oral communication. The comparison reveals a number of interesting features of the English words that Japanese students are supposed to learn in junior high and high school English education. This paper focuses on characteristic English words observed only in the speech corpus-based vocabulary list, which include not only groups of common nouns, verbs, adjectives, and adverbs, but also some oral communication–oriented items such as contracted forms, interjections, discourse particles, and so forth. Analysis of these vocabulary items will show what sorts of words are viewed as necessary for Japanese English learners to further develop their English communication abilities after having learned the fundamental 3,000 English vocabulary items included in officially approved textbooks. This paper is an extension of Yamamoto (2015), which focused on 507 vocabulary items that must appear in each officially approved Japanese junior high school English textbook.

本研究は，JSPS科研費（25770205）に基づくものである。