This edition is written in English. However, there is a running Korean thesaurus at the bottom of each page for the more difficult English words highlighted in the text. There are many editions of Diary, Oct-Nov-Dec 1660. This edition would be useful if you would like to enrich your Korean-English vocabulary, whether for self-improvement or for preparation in advanced of college examinations. Websters edition of this classic is organized to expose the reader to a maximum number of difficult and potentially ambiguous English words. Rare or idiosyncratic words and expressions are given lower priority compared to difficult, yet commonly used English words. Rather than supply a single translation, many words are translated for a variety of meanings in Korean, allowing readers to better grasp the ambiguity of English without using the notes as a pure translation crutch. Having the reader decipher a words meaning within context serves to improve vocabulary retention and understanding. Each page covers words not already highlighted on previous pages. This edition is helpful to Korean-speaking students enrolled in an English Language Program (ELP), an English as a Foreign Language (EFL) program, an English as a Second Language Program (ESL), or in a TOEFL® or TOEIC® preparation program. Students who are actively building their vocabularies in Korean or English may also find this useful for Advanced Placement® (AP®) tests. TOEFL®, TOEIC®, AP® and Advanced Placement® are trademarks of the Educational Testing Service which has neither reviewed nor endorsed this book. This book is one of a series of Websters paperbacks that allows the reader to obtain more value from the experience of reading. Translations are from Websters Online Dictionary, derived from a meta-analysis of public sources, cited on the site.