This article reports on a part of the development and validation project for the English Vocabulary Profile (EVP). The previous version of the EVP included 439 phrasal verbs as well as 4,666 individual word entries. Each of their meanings is ordered according to its CEFR level. The aims of the study are to identify the actual difficulty of each phrasal verb, to validate the tentative decision of the CEFR levels, and also to explore factors that explain the difficulties, by using textbook corpora. In order to carry out this research, we developed a phrasal verb test of 100 items, consisting of four A1 items, nineteen A2 items, forty B1 items and thirty-seven B2 items. Approximately 1,600 Japanese students took this test. We analysed the test data, using item response theory. The results of the test show that although the average difficulties of the phrasal verbs in each level were ordered according to the level prediction, the ranges of the difficulties in each level overlapped. The analysis of textbook corpora reveals that there is a complex relationship between the difficulty levels of phrasal verbs and their frequencies in the textbooks. We discuss its implications and possible improvements for the EVP.