QUARTET is divided into two volumes. QUARTET 1 is designed for learners who have completed the beginning level (250–300 hours of study), while QUARTET 2 serves those who have finished the early stage of intermediate studies (350–400 hours, including beginning studies).

Since QUARTET uses English to explain grammar points and reading strategies, and provides English translations of vocabulary terms, English speakers should be able to use it for self-study. Its effectiveness as a self-study resource is enhanced when used in conjunction with the workbook (containing questions of the content of readings, and exercises for the grammatical patterns and expressions) and the exclusive apps for vocabulary and kanji practice.

Used as suggested, QUARTET 1 and 2 each take around 100 hours to complete, totaling approximately 200 hours of instruction. As a general guide, each lesson spans 16 hours, comprising 8 hours for Reading (including grammatical patterns and expressions), 2 hours for Writing, 3 hours for Speaking, 1 hour for Listening, and 2 hours for Brush-up. (Here, one hour is a literal hour, i.e., 60 minutes.)

The flexibility of QUARTET’s design enables teachers to make tweaks needed to accommodate courses with less time available. For example, the instructor can choose to assign the Reading section’s grammatical patterns/expressions and the Brush-up section as homework, or reduce the number of dialogues, listening exercises, and readings to one each. Another approach is to adjust the weight of each section to match the curriculum and learners’ needs.

Each lesson assumes that the content of preceding lessons has been studied. This means, for example, that grammatical patterns and expressions learned in Lesson 1 are not accompanied by 文型・表現ノート commentary when they reappear in subsequent units. Also, English translations and kanji readings are not provided for words and kanji already studied. Since QUARTET 1 (Lessons 1–6) covers many frequently used grammatical patterns, expressions, words, and kanji, we recommend that these six units be studied in the order they appear. However, QUARTET 2 (Lessons 7–12) can be more easily tailored to the learners’ interests and needs, such as by changing the lesson order or omitting certain lessons.

It is not necessary to go through these sections in order, but it is advisable to always start with the Reading section because it introduces new grammatical patterns and expressions that appear in the other sections. This is especially true for the Writing section, since its composition exercises are based on the reading material studied in Reading.

QUARTET presents 657 kanji for study, 327 in volume 1 and 330 in volume 2. Since QUARTET assumes that learners have already been exposed to the 317 kanji covered by GENKI: An Integrated Course in Elementary Japanese, it does not introduce those characters as learning targets. Accordingly, learners who have completed GENKI and QUARTET will have studied roughly 974 kanji.

QUARTET introduces approximately 1,600 vocabulary terms for study as words appearing in the reading material. Volumes 1 and 2 cover roughly 700 and 900 terms, respectively. Particularly important words are presented as learning focuses. Each lesson covers 42 to 45 terms, whose usage can be learned from not only the readings, but also the example sentences.

The textbooks’ audio material can be downloaded via the QUARTET page on The Japan Times Publishing’s Book Club website, or the OTO Navi – Sound Navigator app.
Resources
The Japan Times Publishing’s “OTO Navi - Sound Navigator” app
The audio files contain recordings of each lesson’s 読み物1/読み物2 readings, the first example sentence of each item in 文型・表現ノート, the 会話1/会話2 model dialogues, and the 聴解1/聴解2 listening exercises, as well as the Supplement’s 覚える単語と例文.

Consider using “QUARTET Vocab & Kanji” and “QUARTET2 Vocab & Kanji,” two apps exclusively designed to aid QUARTET users (iOS and Android). These help learners overcome the frustration of dealing with the many kanji and vocabulary terms covered at the intermediate level by enabling them to practice anywhere, anytime.
Related apps created by the authors